Use PRODUCT_BUNDLE_IDENTIFIER from buildSettings to find correct bundle id on iOS when using flavors (#42964)

packages/flutter_tools/lib/src/ios/devices.dart

@@ -267,6 +267,9 @@ class IOSDevice extends Device {
     bool prebuiltApplication = false,
     bool ipv6 = false,
   }) async {
+
+    String packageId;
+
     if (!prebuiltApplication) {
       // TODO(chinmaygarde): Use mainPath, route.
       printTrace('Building ${package.name} for $id');
@@ -288,12 +291,15 @@ class IOSDevice extends Device {
         printError('');
         return LaunchResult.failed();
       }
+      packageId = buildResult.xcodeBuildExecution?.buildSettings['PRODUCT_BUNDLE_IDENTIFIER'];
     } else {
       if (!await installApp(package)) {
         return LaunchResult.failed();
       }
     }
 
+    packageId ??= package.id;
+
     // Step 2: Check that the application exists at the specified path.
     final IOSApp iosApp = package;
     final Directory bundle = fs.directory(iosApp.deviceBundlePath);
@@ -367,7 +373,7 @@ class IOSDevice extends Device {
       try {
         printTrace('Application launched on the device. Waiting for observatory port.');
         localUri = await MDnsObservatoryDiscovery.instance.getObservatoryUri(
-          package.id,
+          packageId,
           this,
           ipv6,
           debuggingOptions.observatoryPort,

packages/flutter_tools/lib/src/ios/mac.dart

@@ -562,7 +562,16 @@ Future<XcodeBuildResult> buildXcodeProject({
     } else {
       printError('Build succeeded but the expected app at $expectedOutputDirectory not found');
     }
-    return XcodeBuildResult(success: true, output: outputDir);
+    return XcodeBuildResult(
+        success: true,
+        output: outputDir,
+        xcodeBuildExecution: XcodeBuildExecution(
+          buildCommands: buildCommands,
+          appDirectory: app.project.hostAppRoot.path,
+          buildForPhysicalDevice: buildForDevice,
+          buildSettings: buildSettings,
+      ),
+    );
   }
 }