Move plugin injection to just after pub get (#14743)

packages/flutter_tools/lib/src/ios/mac.dart

diff --git a/packages/flutter_tools/lib/src/ios/mac.dart b/packages/flutter_tools/lib/src/ios/mac.dart
index 32d37b1..b2a5f6f 100644
--- a/packages/flutter_tools/lib/src/ios/mac.dart
+++ b/packages/flutter_tools/lib/src/ios/mac.dart
@@ -219,7 +219,7 @@
     return new XcodeBuildResult(success: false);
   }
 
-  final XcodeProjectInfo projectInfo = new XcodeProjectInfo.fromProjectSync(app.appDirectory);
+  final XcodeProjectInfo projectInfo = xcodeProjectInterpreter.getInfo(app.appDirectory);
   if (!projectInfo.targets.contains('Runner')) {
     printError('The Xcode project does not define target "Runner" which is needed by Flutter tooling.');
     printError('Open Xcode to fix the problem:');
@@ -256,26 +256,22 @@
   // copied over to a location that is suitable for Xcodebuild to find them.
   final Directory appDirectory = fs.directory(app.appDirectory);
   await _addServicesToBundle(appDirectory);
-  final InjectPluginsResult injectPluginsResult = injectPlugins();
-  final bool hasFlutterPlugins = injectPluginsResult.hasPlugin;
   final String previousGeneratedXcconfig = readGeneratedXcconfig(app.appDirectory);
 
-  updateXcodeGeneratedProperties(
+  updateGeneratedXcodeProperties(
     projectPath: fs.currentDirectory.path,
     buildInfo: buildInfo,
     target: target,
-    hasPlugins: hasFlutterPlugins,
     previewDart2: buildInfo.previewDart2,
   );
 
-  if (hasFlutterPlugins) {
+  if (hasPlugins()) {
     final String currentGeneratedXcconfig = readGeneratedXcconfig(app.appDirectory);
     await cocoaPods.processPods(
-        appIosDir: appDirectory,
-        iosEngineDir: flutterFrameworkDir(buildInfo.mode),
-        isSwift: app.isSwift,
-        pluginOrFlutterPodChanged: injectPluginsResult.hasChanged
-            || previousGeneratedXcconfig != currentGeneratedXcconfig,
+      appIosDir: appDirectory,
+      iosEngineDir: flutterFrameworkDir(buildInfo.mode),
+      isSwift: app.isSwift,
+      flutterPodChanged: (previousGeneratedXcconfig != currentGeneratedXcconfig),
     );
   }
 
@@ -465,7 +461,7 @@
 
 String readGeneratedXcconfig(String appPath) {
   final String generatedXcconfigPath =
-      fs.path.join(fs.currentDirectory.path, appPath, 'Flutter','Generated.xcconfig');
+      fs.path.join(fs.currentDirectory.path, appPath, 'Flutter', 'Generated.xcconfig');
   final File generatedXcconfigFile = fs.file(generatedXcconfigPath);
   if (!generatedXcconfigFile.existsSync())
     return null;