[in_app_purchase] Bump minimum Flutter version and iOS deployment target (#4352)

diff --git a/packages/in_app_purchase/in_app_purchase_ios/CHANGELOG.md b/packages/in_app_purchase/in_app_purchase_ios/CHANGELOG.md
index e66b5de..04509e5 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/CHANGELOG.md
+++ b/packages/in_app_purchase/in_app_purchase_ios/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.1.3+4
+
+* Update minimum Flutter SDK to 2.5 and iOS deployment target to 9.0.
+
 ## 0.1.3+3
 
 * Add `implements` to pubspec.
diff --git a/packages/in_app_purchase/in_app_purchase_ios/README.md b/packages/in_app_purchase/in_app_purchase_ios/README.md
index fcd4834..7ac21c4 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/README.md
+++ b/packages/in_app_purchase/in_app_purchase_ios/README.md
@@ -24,6 +24,6 @@
 [contribution guide](https://github.com/flutter/plugins/blob/master/CONTRIBUTING.md).
 
 
-[1]: ../in_app_purchase/in_app_purchase
+[1]: ../in_app_purchase
 [2]: https://flutter.dev/docs/development/packages-and-plugins/developing-packages#endorsed-federated-plugin
 [3]: https://pub.dev/packages/in_app_purchase_ios/install
diff --git a/packages/in_app_purchase/in_app_purchase_ios/example/ios/Flutter/AppFrameworkInfo.plist b/packages/in_app_purchase/in_app_purchase_ios/example/ios/Flutter/AppFrameworkInfo.plist
index 9367d48..8d4492f 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/example/ios/Flutter/AppFrameworkInfo.plist
+++ b/packages/in_app_purchase/in_app_purchase_ios/example/ios/Flutter/AppFrameworkInfo.plist
@@ -21,6 +21,6 @@
   <key>CFBundleVersion</key>
   <string>1.0</string>
   <key>MinimumOSVersion</key>
-  <string>8.0</string>
+  <string>9.0</string>
 </dict>
 </plist>
diff --git a/packages/in_app_purchase/in_app_purchase_ios/example/ios/Runner.xcodeproj/project.pbxproj b/packages/in_app_purchase/in_app_purchase_ios/example/ios/Runner.xcodeproj/project.pbxproj
index 61a5da6..a880501 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/example/ios/Runner.xcodeproj/project.pbxproj
+++ b/packages/in_app_purchase/in_app_purchase_ios/example/ios/Runner.xcodeproj/project.pbxproj
@@ -489,7 +489,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = YES;
 				ONLY_ACTIVE_ARCH = YES;
 				SDKROOT = iphoneos;
@@ -539,7 +539,7 @@
 				GCC_WARN_UNINITIALIZED_AUTOS = YES_AGGRESSIVE;
 				GCC_WARN_UNUSED_FUNCTION = YES;
 				GCC_WARN_UNUSED_VARIABLE = YES;
-				IPHONEOS_DEPLOYMENT_TARGET = 8.0;
+				IPHONEOS_DEPLOYMENT_TARGET = 9.0;
 				MTL_ENABLE_DEBUG_INFO = NO;
 				SDKROOT = iphoneos;
 				TARGETED_DEVICE_FAMILY = "1,2";
diff --git a/packages/in_app_purchase/in_app_purchase_ios/example/ios/RunnerTests/InAppPurchasePluginTests.m b/packages/in_app_purchase/in_app_purchase_ios/example/ios/RunnerTests/InAppPurchasePluginTests.m
index 79812f6..b51f622 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/example/ios/RunnerTests/InAppPurchasePluginTests.m
+++ b/packages/in_app_purchase/in_app_purchase_ios/example/ios/RunnerTests/InAppPurchasePluginTests.m
@@ -169,11 +169,7 @@
           transactionForUpdateBlock = transaction;
           [expectation fulfill];
         }
-        if (@available(iOS 8.3, *)) {
-          if (!transaction.payment.simulatesAskToBuyInSandbox) {
-            [simulatesAskToBuyInSandboxExpectation fulfill];
-          }
-        } else {
+        if (!transaction.payment.simulatesAskToBuyInSandbox) {
           [simulatesAskToBuyInSandboxExpectation fulfill];
         }
       }
diff --git a/packages/in_app_purchase/in_app_purchase_ios/example/pubspec.yaml b/packages/in_app_purchase/in_app_purchase_ios/example/pubspec.yaml
index b916990..0474d70 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/example/pubspec.yaml
+++ b/packages/in_app_purchase/in_app_purchase_ios/example/pubspec.yaml
@@ -3,8 +3,8 @@
 publish_to: none
 
 environment:
-  sdk: ">=2.12.0 <3.0.0"
-  flutter: ">=1.9.1+hotfix.2"
+  sdk: ">=2.14.0 <3.0.0"
+  flutter: ">=2.5.0"
 
 dependencies:
   flutter:
diff --git a/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/FIAObjectTranslator.m b/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/FIAObjectTranslator.m
index 765ef4d..0125604 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/FIAObjectTranslator.m
+++ b/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/FIAObjectTranslator.m
@@ -96,9 +96,7 @@
     @"quantity" : @(payment.quantity),
     @"applicationUsername" : payment.applicationUsername ?: [NSNull null]
   }];
-  if (@available(iOS 8.3, *)) {
-    [map setObject:@(payment.simulatesAskToBuyInSandbox) forKey:@"simulatesAskToBuyInSandbox"];
-  }
+  [map setObject:@(payment.simulatesAskToBuyInSandbox) forKey:@"simulatesAskToBuyInSandbox"];
   return map;
 }
 
@@ -125,9 +123,7 @@
   payment.requestData = [utf8String dataUsingEncoding:NSUTF8StringEncoding];
   payment.quantity = [map[@"quantity"] integerValue];
   payment.applicationUsername = map[@"applicationUsername"];
-  if (@available(iOS 8.3, *)) {
-    payment.simulatesAskToBuyInSandbox = [map[@"simulatesAskToBuyInSandbox"] boolValue];
-  }
+  payment.simulatesAskToBuyInSandbox = [map[@"simulatesAskToBuyInSandbox"] boolValue];
   return payment;
 }
 
diff --git a/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/InAppPurchasePlugin.m b/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/InAppPurchasePlugin.m
index c0db38e..7e2d2ca 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/InAppPurchasePlugin.m
+++ b/packages/in_app_purchase/in_app_purchase_ios/ios/Classes/InAppPurchasePlugin.m
@@ -198,12 +198,10 @@
   payment.applicationUsername = [paymentMap objectForKey:@"applicationUsername"];
   NSNumber *quantity = [paymentMap objectForKey:@"quantity"];
   payment.quantity = (quantity != nil) ? quantity.integerValue : 1;
-  if (@available(iOS 8.3, *)) {
-    NSNumber *simulatesAskToBuyInSandbox = [paymentMap objectForKey:@"simulatesAskToBuyInSandbox"];
-    payment.simulatesAskToBuyInSandbox = (id)simulatesAskToBuyInSandbox == (id)[NSNull null]
-                                             ? NO
-                                             : [simulatesAskToBuyInSandbox boolValue];
-  }
+  NSNumber *simulatesAskToBuyInSandbox = [paymentMap objectForKey:@"simulatesAskToBuyInSandbox"];
+  payment.simulatesAskToBuyInSandbox = (id)simulatesAskToBuyInSandbox == (id)[NSNull null]
+                                           ? NO
+                                           : [simulatesAskToBuyInSandbox boolValue];
 
   if (![self.paymentQueueHandler addPayment:payment]) {
     result([FlutterError
diff --git a/packages/in_app_purchase/in_app_purchase_ios/ios/in_app_purchase_ios.podspec b/packages/in_app_purchase/in_app_purchase_ios/ios/in_app_purchase_ios.podspec
index 7852353..3d15b5c 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/ios/in_app_purchase_ios.podspec
+++ b/packages/in_app_purchase/in_app_purchase_ios/ios/in_app_purchase_ios.podspec
@@ -19,6 +19,6 @@
   s.source_files = 'Classes/**/*'
   s.public_header_files = 'Classes/**/*.h'
   s.dependency 'Flutter'
-  s.platform = :ios, '8.0'
-  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'VALID_ARCHS' => 'armv7 arm64 x86_64' }
+  s.platform = :ios, '9.0'
+  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES' }
 end
diff --git a/packages/in_app_purchase/in_app_purchase_ios/pubspec.yaml b/packages/in_app_purchase/in_app_purchase_ios/pubspec.yaml
index 07eae3c..9ba642e 100644
--- a/packages/in_app_purchase/in_app_purchase_ios/pubspec.yaml
+++ b/packages/in_app_purchase/in_app_purchase_ios/pubspec.yaml
@@ -2,11 +2,11 @@
 description: An implementation for the iOS platform of the Flutter `in_app_purchase` plugin. This uses the iOS StoreKit Framework.
 repository: https://github.com/flutter/plugins/tree/master/packages/in_app_purchase/in_app_purchase_ios
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+in_app_purchase%22
-version: 0.1.3+3
+version: 0.1.3+4
 
 environment:
-  sdk: ">=2.12.0 <3.0.0"
-  flutter: ">=2.0.0"
+  sdk: ">=2.14.0 <3.0.0"
+  flutter: ">=2.5.0"
 
 flutter:
   plugin: