Copy the local engine repo in the output directory (#49276)

packages/flutter_tools/lib/src/android/gradle.dart

@@ -546,6 +546,19 @@ Future<void> buildGradleAar({
     command.add('-Plocal-engine-repo=${localEngineRepo.path}');
     command.add('-Plocal-engine-build-mode=${androidBuildInfo.buildInfo.modeName}');
     command.add('-Plocal-engine-out=${localEngineArtifacts.engineOutPath}');
+
+    // Copy the local engine repo in the output directory.
+    try {
+      fsUtils.copyDirectorySync(
+        localEngineRepo,
+        getRepoDirectory(outputDirectory),
+      );
+    } on FileSystemException catch(_) {
+      throwToolExit(
+        'Failed to copy the local engine ${localEngineRepo.path} repo '
+        'in ${outputDirectory.path}'
+      );
+    }
   }
 
   command.add(aarTask);

packages/flutter_tools/test/general.shard/android/gradle_test.dart

@@ -1055,10 +1055,12 @@ plugin1=${plugin1.path}
     MockProcessManager mockProcessManager;
     FakePlatform android;
     FileSystem fileSystem;
+    FileSystemUtils fileSystemUtils;
     Cache cache;
 
     setUp(() {
       fileSystem = MemoryFileSystem();
+      fileSystemUtils = MockFileSystemUtils();
       mockAndroidSdk = MockAndroidSdk();
       mockAndroidStudio = MockAndroidStudio();
       mockArtifacts = MockLocalEngineArtifacts();
@@ -1773,6 +1775,12 @@ plugin1=${plugin1.path}
         '''
       );
 
+      fileSystem.directory('.android/gradle')
+        .createSync(recursive: true);
+
+      fileSystem.directory('.android/gradle/wrapper')
+        .createSync(recursive: true);
+
       fileSystem.file('.android/gradlew').createSync(recursive: true);
 
       fileSystem.file('.android/gradle.properties')
@@ -1790,6 +1798,8 @@ plugin1=${plugin1.path}
 
       fileSystem.directory('build/outputs/repo').createSync(recursive: true);
 
+      when(fileSystemUtils.copyDirectorySync(any, any)).thenReturn(null);
+
       await buildGradleAar(
         androidBuildInfo: const AndroidBuildInfo(BuildInfo(BuildMode.release, null)),
         project: FlutterProject.current(),
@@ -1812,6 +1822,15 @@ plugin1=${plugin1.path}
       expect(actualGradlewCall, contains('-Plocal-engine-build-mode=release'));
       expect(actualGradlewCall, contains('-PbuildNumber=2.0'));
 
+      // Verify the local engine repo is copied into the generated Maven repo.
+      final List<dynamic> copyDirectoryArguments = verify(
+        fileSystemUtils.copyDirectorySync(captureAny, captureAny)
+      ).captured;
+
+      expect(copyDirectoryArguments.length, 2);
+      expect((copyDirectoryArguments.first as Directory).path, '/.tmp_rand0/flutter_tool_local_engine_repo.rand0');
+      expect((copyDirectoryArguments.last as Directory).path, 'build/outputs/repo');
+
     }, overrides: <Type, Generator>{
       AndroidSdk: () => mockAndroidSdk,
       AndroidStudio: () => mockAndroidStudio,
@@ -1819,6 +1838,7 @@ plugin1=${plugin1.path}
       Cache: () => cache,
       Platform: () => android,
       FileSystem: () => fileSystem,
+      FileSystemUtils: () => fileSystemUtils,
       ProcessManager: () => mockProcessManager,
     });
   });
@@ -2047,6 +2067,7 @@ class MockAndroidProject extends Mock implements AndroidProject {}
 class MockAndroidStudio extends Mock implements AndroidStudio {}
 class MockDirectory extends Mock implements Directory {}
 class MockFile extends Mock implements File {}
+class MockFileSystemUtils extends Mock implements FileSystemUtils {}
 class MockFlutterProject extends Mock implements FlutterProject {}
 class MockLocalEngineArtifacts extends Mock implements LocalEngineArtifacts {}
 class MockProcessManager extends Mock implements ProcessManager {}