[flutter_tools] move gradle helper methods into AndroidBuilder class body, split unit tests (#75931)

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

@@ -6,21 +6,15 @@
 
 import 'package:meta/meta.dart';
 
-import '../android/gradle_errors.dart';
 import '../base/context.dart';
-import '../base/file_system.dart';
 import '../build_info.dart';
-import '../globals.dart' as globals;
 import '../project.dart';
-import 'gradle.dart';
 
 /// The builder in the current context.
 AndroidBuilder get androidBuilder {
-  return context.get<AndroidBuilder>() ?? const _AndroidBuilderImpl();
+  return context.get<AndroidBuilder>();
 }
 
-/// Provides the methods to build Android artifacts.
-// TODO(egarciad): https://github.com/flutter/flutter/issues/43863
 abstract class AndroidBuilder {
   const AndroidBuilder();
   /// Builds an AAR artifact.
@@ -46,89 +40,3 @@ abstract class AndroidBuilder {
     @required String target,
   });
 }
-
-/// Default implementation of [AarBuilder].
-class _AndroidBuilderImpl extends AndroidBuilder {
-  const _AndroidBuilderImpl();
-
-  /// Builds the AAR and POM files for the current Flutter module or plugin.
-  @override
-  Future<void> buildAar({
-    @required FlutterProject project,
-    @required Set<AndroidBuildInfo> androidBuildInfo,
-    @required String target,
-    @required String outputDirectoryPath,
-    @required String buildNumber,
-  }) async {
-    try {
-      Directory outputDirectory =
-        globals.fs.directory(outputDirectoryPath ?? project.android.buildDirectory);
-      if (project.isModule) {
-        // Module projects artifacts are located in `build/host`.
-        outputDirectory = outputDirectory.childDirectory('host');
-      }
-      for (final AndroidBuildInfo androidBuildInfo in androidBuildInfo) {
-        await buildGradleAar(
-          project: project,
-          androidBuildInfo: androidBuildInfo,
-          target: target,
-          outputDirectory: outputDirectory,
-          buildNumber: buildNumber,
-        );
-      }
-      printHowToConsumeAar(
-        buildModes: androidBuildInfo
-          .map<String>((AndroidBuildInfo androidBuildInfo) {
-            return androidBuildInfo.buildInfo.modeName;
-          }).toSet(),
-        androidPackage: project.manifest.androidPackage,
-        repoDirectory: getRepoDirectory(outputDirectory),
-        buildNumber: buildNumber,
-        logger: globals.logger,
-        fileSystem: globals.fs,
-      );
-    } finally {
-      globals.androidSdk?.reinitialize();
-    }
-  }
-
-  /// Builds the APK.
-  @override
-  Future<void> buildApk({
-    @required FlutterProject project,
-    @required AndroidBuildInfo androidBuildInfo,
-    @required String target,
-  }) async {
-    try {
-      await buildGradleApp(
-        project: project,
-        androidBuildInfo: androidBuildInfo,
-        target: target,
-        isBuildingBundle: false,
-        localGradleErrors: gradleErrors,
-      );
-    } finally {
-      globals.androidSdk?.reinitialize();
-    }
-  }
-
-  /// Builds the App Bundle.
-  @override
-  Future<void> buildAab({
-    @required FlutterProject project,
-    @required AndroidBuildInfo androidBuildInfo,
-    @required String target,
-  }) async {
-    try {
-      await buildGradleApp(
-        project: project,
-        androidBuildInfo: androidBuildInfo,
-        target: target,
-        isBuildingBundle: true,
-        localGradleErrors: gradleErrors,
-      );
-    } finally {
-      globals.androidSdk?.reinitialize();
-    }
-  }
-}

packages/flutter_tools/lib/src/context_runner.dart

@@ -8,9 +8,11 @@ import 'dart:async';
 
 import 'package:process/process.dart';
 
+import 'android/android_builder.dart';
 import 'android/android_sdk.dart';
 import 'android/android_studio.dart';
 import 'android/android_workflow.dart';
+import 'android/gradle.dart';
 import 'android/gradle_utils.dart';
 import 'application_package.dart';
 import 'artifacts.dart';
@@ -77,6 +79,7 @@ Future<T> runInContext<T>(
     body: runnerWrapper,
     overrides: overrides,
     fallbacks: <Type, Generator>{
+      AndroidBuilder: () => AndroidGradleBuilder(),
       AndroidLicenseValidator: () => AndroidLicenseValidator(
         operatingSystemUtils: globals.os,
         platform: globals.platform,