Change iOS plugin simulator archs from allow list to deny list (#64504)

diff --git a/dev/devicelab/bin/tasks/plugin_lint_mac.dart b/dev/devicelab/bin/tasks/plugin_lint_mac.dart
index e815258..d9693f3 100644
--- a/dev/devicelab/bin/tasks/plugin_lint_mac.dart
+++ b/dev/devicelab/bin/tasks/plugin_lint_mac.dart
@@ -45,6 +45,7 @@
             'lint',
             objcPodspecPath,
             '--allow-warnings',
+            '--verbose',
           ],
           environment: <String, String>{
             'LANG': 'en_US.UTF-8',
@@ -63,6 +64,7 @@
             objcPodspecPath,
             '--allow-warnings',
             '--use-libraries',
+            '--verbose',
           ],
           environment: <String, String>{
             'LANG': 'en_US.UTF-8',
diff --git a/packages/flutter_tools/templates/plugin/ios-objc.tmpl/projectName.podspec.tmpl b/packages/flutter_tools/templates/plugin/ios-objc.tmpl/projectName.podspec.tmpl
index faecbe5..67c0111 100644
--- a/packages/flutter_tools/templates/plugin/ios-objc.tmpl/projectName.podspec.tmpl
+++ b/packages/flutter_tools/templates/plugin/ios-objc.tmpl/projectName.podspec.tmpl
@@ -18,6 +18,6 @@
   s.dependency 'Flutter'
   s.platform = :ios, '8.0'
 
-  # Flutter.framework does not contain a i386 slice. Only x86_64 simulators are supported.
-  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'VALID_ARCHS[sdk=iphonesimulator*]' => 'x86_64' }
+  # Flutter.framework does not contain a i386 slice.
+  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }
 end
diff --git a/packages/flutter_tools/templates/plugin/ios-swift.tmpl/projectName.podspec.tmpl b/packages/flutter_tools/templates/plugin/ios-swift.tmpl/projectName.podspec.tmpl
index 1a60d14..df2a8bd 100644
--- a/packages/flutter_tools/templates/plugin/ios-swift.tmpl/projectName.podspec.tmpl
+++ b/packages/flutter_tools/templates/plugin/ios-swift.tmpl/projectName.podspec.tmpl
@@ -17,7 +17,7 @@
   s.dependency 'Flutter'
   s.platform = :ios, '8.0'
 
-  # Flutter.framework does not contain a i386 slice. Only x86_64 simulators are supported.
-  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'VALID_ARCHS[sdk=iphonesimulator*]' => 'x86_64' }
+  # Flutter.framework does not contain a i386 slice.
+  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }
   s.swift_version = '5.0'
 end