Stop recommending android sdk root (#136296)

Fixes https://github.com/flutter/flutter/issues/117245

dev/devicelab/lib/framework/apk_utils.dart

@@ -107,7 +107,7 @@ String get _androidHome {
   final String? androidHome = Platform.environment['ANDROID_HOME'] ??
       Platform.environment['ANDROID_SDK_ROOT'];
   if (androidHome == null || androidHome.isEmpty) {
-    throw Exception('Environment variable `ANDROID_SDK_ROOT` is not set.');
+    throw Exception('Environment variable `ANDROID_HOME` is not set.');
   }
   return androidHome;
 }

dev/devicelab/lib/framework/devices.dart

@@ -1346,7 +1346,7 @@ String get adbPath {
 
   if (androidHome == null) {
     throw const DeviceException(
-      'The ANDROID_SDK_ROOT environment variable is '
+      'The ANDROID_HOME environment variable is '
       'missing. The variable must point to the Android '
       'SDK directory containing platform-tools.'
     );

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

@@ -74,7 +74,7 @@ class AndroidDevices extends PollingDeviceDiscovery {
     } on ProcessException catch (exception) {
       throwToolExit(
         'Unable to run "adb", check your Android SDK installation and '
-        '$kAndroidSdkRoot environment variable: ${exception.executable}',
+        '$kAndroidHome environment variable: ${exception.executable}',
       );
     }
     final List<AndroidDevice> devices = <AndroidDevice>[];

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

@@ -10,27 +10,27 @@ import '../convert.dart';
 import '../globals.dart' as globals;
 import 'java.dart';
 
-// ANDROID_HOME is deprecated.
+// ANDROID_SDK_ROOT is deprecated.
 // See https://developer.android.com/studio/command-line/variables.html#envar
-const String kAndroidHome = 'ANDROID_HOME';
 const String kAndroidSdkRoot = 'ANDROID_SDK_ROOT';
+const String kAndroidHome = 'ANDROID_HOME';
 
 final RegExp _numberedAndroidPlatformRe = RegExp(r'^android-([0-9]+)$');
 final RegExp _sdkVersionRe = RegExp(r'^ro.build.version.sdk=([0-9]+)$');
 
 // Android SDK layout:
 
-// $ANDROID_SDK_ROOT/platform-tools/adb
+// $ANDROID_HOME/platform-tools/adb
 
-// $ANDROID_SDK_ROOT/build-tools/19.1.0/aapt, dx, zipalign
-// $ANDROID_SDK_ROOT/build-tools/22.0.1/aapt
-// $ANDROID_SDK_ROOT/build-tools/23.0.2/aapt
-// $ANDROID_SDK_ROOT/build-tools/24.0.0-preview/aapt
-// $ANDROID_SDK_ROOT/build-tools/25.0.2/apksigner
+// $ANDROID_HOME/build-tools/19.1.0/aapt, dx, zipalign
+// $ANDROID_HOME/build-tools/22.0.1/aapt
+// $ANDROID_HOME/build-tools/23.0.2/aapt
+// $ANDROID_HOME/build-tools/24.0.0-preview/aapt
+// $ANDROID_HOME/build-tools/25.0.2/apksigner
 
-// $ANDROID_SDK_ROOT/platforms/android-22/android.jar
-// $ANDROID_SDK_ROOT/platforms/android-23/android.jar
-// $ANDROID_SDK_ROOT/platforms/android-N/android.jar
+// $ANDROID_HOME/platforms/android-22/android.jar
+// $ANDROID_HOME/platforms/android-23/android.jar
+// $ANDROID_HOME/platforms/android-N/android.jar
 class AndroidSdk {
   AndroidSdk(this.directory, {
     Java? java,

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

@@ -742,7 +742,7 @@ void exitWithNoSdkMessage() {
           flutterUsage: globals.flutterUsage)
       .send();
   throwToolExit('${globals.logger.terminal.warningMark} No Android SDK found. '
-      'Try setting the ANDROID_SDK_ROOT environment variable.');
+      'Try setting the ANDROID_HOME environment variable.');
 }
 
 // Data class to hold normal/defined Java <-> Gradle compatability criteria.

packages/flutter_tools/test/commands.shard/permeable/build_aar_test.dart

@@ -228,7 +228,7 @@ void main() {
             arguments: <String>['--no-pub'],
           );
         }, throwsToolExit(
-          message: 'No Android SDK found. Try setting the ANDROID_SDK_ROOT environment variable',
+          message: 'No Android SDK found. Try setting the ANDROID_HOME environment variable',
         ));
       },
       overrides: <Type, Generator>{

packages/flutter_tools/test/commands.shard/permeable/build_apk_test.dart

@@ -138,7 +138,7 @@ void main() {
             arguments: <String>['--no-pub'],
           ),
           throwsToolExit(
-            message: 'No Android SDK found. Try setting the ANDROID_SDK_ROOT environment variable',
+            message: 'No Android SDK found. Try setting the ANDROID_HOME environment variable',
           ),
         );
       },

packages/flutter_tools/test/commands.shard/permeable/build_appbundle_test.dart

@@ -113,7 +113,7 @@ void main() {
             arguments: <String>['--no-pub'],
           );
         }, throwsToolExit(
-          message: 'No Android SDK found. Try setting the ANDROID_SDK_ROOT environment variable',
+          message: 'No Android SDK found. Try setting the ANDROID_HOME environment variable',
         ));
       },
       overrides: <Type, Generator>{

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

@@ -198,7 +198,7 @@ void main() {
       expect(() {
         gradle_utils.updateLocalProperties(project: FlutterProject.fromDirectoryTest(globals.fs.currentDirectory));
       }, throwsToolExit(
-        message: '${globals.logger.terminal.warningMark} No Android SDK found. Try setting the ANDROID_SDK_ROOT environment variable.',
+        message: '${globals.logger.terminal.warningMark} No Android SDK found. Try setting the ANDROID_HOME environment variable.',
       ));
     }, overrides: <Type, Generator>{
       AndroidSdk: () => null,