Load macOS dart bundle by URL fallback (flutter#22979)

Author: jmagman

shell/platform/darwin/macos/framework/Source/FlutterDartProject.mm

@@ -27,6 +27,11 @@ - (instancetype)initWithPrecompiledDartBundle:(NSBundle*)bundle {
   NSAssert(self, @"Super init cannot be nil");
 
   _dartBundle = bundle ?: [NSBundle bundleWithIdentifier:kAppBundleIdentifier];
+  if (_dartBundle == nil) {
+    // The bundle isn't loaded and can't be found by bundle ID. Find it by path.
+    _dartBundle = [NSBundle bundleWithURL:[NSBundle.mainBundle.privateFrameworksURL
+                                              URLByAppendingPathComponent:@"App.framework"]];
+  }
   _dartEntrypointArguments = [[NSProcessInfo processInfo] arguments];
   // Remove the first element as it's the binary name
   _dartEntrypointArguments = [_dartEntrypointArguments