Update getGradleVersion to ignore commented out lines (flutter#124260)

flutter#123917
Missed feedback from flutter#123916 

- Handle commented out lines in gradle-wrapper.properties

This is 1 of 2 prs to handle missed feedback. Formatting will be done in
the second whereas this one captures a weakness missed in the last pr.

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] All existing and new tests are passing.

Author: reidbaker

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

@@ -189,8 +189,9 @@ Future<String?> getGradleVersion(
     // Expected content format (with lines above and below).
     // Version can have 2 or 3 numbers.
     // 'distributionUrl=https\://services.gradle.org/distributions/gradle-7.4.2-all.zip'
+    // '^\s*' protects against commented out lines.
     final RegExp distributionUrlRegex =
-        RegExp(r'distributionUrl\s?=\s?.*\.zip');
+        RegExp(r'^\s*distributionUrl\s?=\s?.*\.zip', multiLine: true);
 
     final RegExpMatch? distributionUrl =
         distributionUrlRegex.firstMatch(wrapperFileContent);

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

@@ -226,6 +226,33 @@ distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
 distributionUrl=https\\://services.gradle.org/distributions/gradle-$expectedVersion-all.zip
+''');
+
+      expect(
+        await getGradleVersion(
+            androidDirectory, BufferLogger.test(), FakeProcessManager.empty()),
+        expectedVersion,
+      );
+    });
+
+        testWithoutContext('ignores gradle comments', () async {
+      const String expectedVersion = '7.4.2';
+      final Directory androidDirectory = fileSystem.directory('/android')
+        ..createSync();
+      final Directory wrapperDirectory = androidDirectory
+          .childDirectory('gradle')
+          .childDirectory('wrapper')
+        ..createSync(recursive: true);
+      wrapperDirectory
+          .childFile('gradle-wrapper.properties')
+          .writeAsStringSync('''
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+# distributionUrl=https\\://services.gradle.org/distributions/gradle-8.0.2-all.zip
+distributionUrl=https\\://services.gradle.org/distributions/gradle-$expectedVersion-all.zip
+# distributionUrl=https\\://services.gradle.org/distributions/gradle-8.0.2-all.zip
 ''');
 
       expect(