Check for AndroidStudio plugins in the right .dot dir. (#20619)

This fixes issues 11940 and 18155.

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

@@ -25,17 +25,19 @@ AndroidStudio get androidStudio => context[AndroidStudio];
 // $HOME/Applications/Android Studio.app/Contents/
 
 final RegExp _dotHomeStudioVersionMatcher =
-    RegExp(r'^\.AndroidStudio([^\d]*)([\d.]+)');
+    RegExp(r'^\.(AndroidStudio[^\d]*)([\d.]+)');
 
 String get javaPath => androidStudio?.javaPath;
 
 class AndroidStudio implements Comparable<AndroidStudio> {
-  AndroidStudio(this.directory, {Version version, this.configured})
+  AndroidStudio(this.directory,
+      {Version version, this.configured, this.studioAppName = 'AndroidStudio'})
       : this.version = version ?? Version.unknown {
     _init();
   }
 
   final String directory;
+  final String studioAppName;
   final Version version;
   final String configured;
 
@@ -65,7 +67,8 @@ class AndroidStudio implements Comparable<AndroidStudio> {
       return null;
     }
     final Version version = Version.parse(versionMatch[2]);
-    if (version == null) {
+    final String studioAppName = versionMatch[1];
+    if (studioAppName == null || version == null) {
       return null;
     }
     String installPath;
@@ -77,7 +80,11 @@ class AndroidStudio implements Comparable<AndroidStudio> {
       // ignored, installPath will be null, which is handled below
     }
     if (installPath != null && fs.isDirectorySync(installPath)) {
-      return AndroidStudio(installPath, version: version);
+      return AndroidStudio(
+          installPath,
+          version: version,
+          studioAppName: studioAppName,
+      );
     }
     return null;
   }
@@ -98,7 +105,7 @@ class AndroidStudio implements Comparable<AndroidStudio> {
             'AndroidStudio$major.$minor');
       } else {
         _pluginsPath = fs.path.join(homeDirPath,
-            '.AndroidStudio$major.$minor',
+            '.$studioAppName$major.$minor',
             'config',
             'plugins');
       }

packages/flutter_tools/test/android/android_studio_test.dart

+import 'package:file/memory.dart';
+import 'package:flutter_tools/src/android/android_studio.dart';
+import 'package:flutter_tools/src/base/file_system.dart';
+import 'package:flutter_tools/src/base/platform.dart';
+
+import '../src/common.dart';
+import '../src/context.dart';
+
+const String home = '/home/me';
+
+Platform linuxPlatform() {
+  return FakePlatform.fromPlatform(const LocalPlatform())
+    ..operatingSystem = 'linux'
+    ..environment = <String, String>{'HOME': home};
+}
+
+void main() {
+  const String installPath = '/opt/android-studio-with-cheese-5.0';
+  const String studioHome = '$home/.AndroidStudioWithCheese5.0';
+  const String homeFile = '$studioHome/system/.home';
+
+  MemoryFileSystem fs;
+
+  setUp(() {
+    fs = MemoryFileSystem();
+    fs.directory(installPath).createSync(recursive: true);
+    fs.file(homeFile).createSync(recursive: true);
+    fs.file(homeFile).writeAsStringSync(installPath);
+  });
+
+  group('pluginsPath', () {
+    testUsingContext('extracts custom paths from home dir', () {
+      final AndroidStudio studio =
+          AndroidStudio.fromHomeDot(fs.directory(studioHome));
+      expect(studio, isNotNull);
+      expect(studio.pluginsPath,
+          equals('/home/me/.AndroidStudioWithCheese5.0/config/plugins'));
+    }, overrides: <Type, Generator>{
+      FileSystem: () => fs,
+      // Note that custom home paths are not supported on macOS nor Windows yet:
+      Platform: () => linuxPlatform(),
+    });
+  });
+}