Fixes incorrect read/write permissions on Flutter.framework and FlutterMacOS.framework (#148580)

Fixes https://github.com/flutter/flutter/issues/148354

Fixes https://github.com/flutter/flutter/issues/147142
Closes https://github.com/flutter/flutter/pull/147144

## 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] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

packages/flutter_tools/lib/src/build_system/targets/ios.dart

@@ -314,6 +314,7 @@ abstract class UnpackIOS extends Target {
       '--delete',
       '--filter',
       '- .DS_Store/',
+      '--chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r',
       basePath,
       environment.outputDir.path,
     ]);

packages/flutter_tools/lib/src/build_system/targets/macos.dart

@@ -60,6 +60,7 @@ abstract class UnpackMacOS extends Target {
       '--delete',
       '--filter',
       '- .DS_Store/',
+      '--chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r',
       basePath,
       environment.outputDir.path,
     ]);

packages/flutter_tools/test/general.shard/build_system/targets/ios_test.dart

@@ -541,6 +541,7 @@ void main() {
         '--delete',
         '--filter',
         '- .DS_Store/',
+        '--chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r',
         'Artifact.flutterFramework.TargetPlatform.ios.debug.EnvironmentType.physical',
         outputDir.path,
       ]);
@@ -597,6 +598,7 @@ void main() {
           '--delete',
           '--filter',
           '- .DS_Store/',
+          '--chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r',
           'Artifact.flutterFramework.TargetPlatform.ios.debug.EnvironmentType.simulator',
           outputDir.path,
           ],

packages/flutter_tools/test/general.shard/build_system/targets/macos_test.dart

@@ -73,6 +73,7 @@ void main() {
         '--delete',
         '--filter',
         '- .DS_Store/',
+        '--chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r',
         'Artifact.flutterMacOSFramework.debug',
         environment.outputDir.path,
       ],
@@ -133,6 +134,7 @@ void main() {
           '--delete',
           '--filter',
           '- .DS_Store/',
+          '--chmod=Du=rwx,Dgo=rx,Fu=rw,Fgo=r',
           // source
           'Artifact.flutterMacOSFramework.debug',
           // destination

packages/flutter_tools/test/host_cross_arch.shard/ios_content_validation_test.dart

@@ -422,10 +422,16 @@ void main() {
           .whereType<Directory>()
           .singleWhere((Directory directory) => fileSystem.path.extension(directory.path) == '.app');
 
+      final Directory flutterFrameworkDir = fileSystem.directory(
+        fileSystem.path.join(
+          appBundle.path,
+          'Frameworks',
+          'Flutter.framework',
+        ),
+      );
+
       final String flutterFramework = fileSystem.path.join(
-        appBundle.path,
-        'Frameworks',
-        'Flutter.framework',
+        flutterFrameworkDir.path,
         'Flutter',
       );
 
@@ -456,6 +462,11 @@ void main() {
         ],
       );
       expect(appCodesign, const ProcessResultMatcher());
+
+      // Check read/write permissions are being correctly set
+      final String rawStatString = flutterFrameworkDir.statSync().modeString();
+      final String statString = rawStatString.substring(rawStatString.length - 9);
+      expect(statString, 'rwxr-xr-x');
     });
   }, skip: !platform.isMacOS, // [intended] only makes sense for macos platform.
      timeout: const Timeout(Duration(minutes: 10))

packages/flutter_tools/test/host_cross_arch.shard/macos_content_validation_test.dart

@@ -164,6 +164,11 @@ void main() {
         ),
       );
 
+      // Check read/write permissions are being correctly set
+      final String rawStatString = outputFlutterFramework.statSync().modeString();
+      final String statString = rawStatString.substring(rawStatString.length - 9);
+      expect(statString, 'rwxr-xr-x');
+
       // Check complicated macOS framework symlink structure.
       final Link current = outputFlutterFramework.childDirectory('Versions').childLink('Current');