Fix Flipper by moving FB_SONARKIT_ENABLED to RCTAppDelegate (#37240)

Summary:
An out-of-the-box react-native init project no longer enables Flipper properly as of 0.72.0-rc1.

## Changelog:

[IOS] [FIXED] Fix Flipper by moving podfile modification of preprocessor def `FB_SONARKIT_ENABLED` from React-Core to React-RCTAppDelegate where it is now used.

Pull Request resolved: #37240

Test Plan: Generated an app and verified Flipper cannot see the app. Made the modification and generated another app and verified Flipper now sees it and can enable plugins. Verified that runtime (non-test) use of FB_SONARKIT_ENABLED is limited to Libraries/AppDelegate in this project.

Reviewed By: dmytrorykun

Differential Revision: D45563282

Pulled By: cipolleschi

fbshipit-source-id: d760c5ae123cc7c967b19c6c626801d6db28d052

packages/react-native/scripts/cocoapods/__tests__/flipper-test.rb

@@ -82,7 +82,7 @@ def test_postInstall_updatesThePodCorrectly
             assert_equal(config.build_settings['SWIFT_VERSION'], '4.1')
         end
 
-        reactCore_target = installer.target_with_name("React-Core")
+        reactCore_target = installer.target_with_name("React-RCTAppDelegate")
         reactCore_target.build_configurations.each do |config|
             if config.name == 'Debug' || config.name == 'CustomConfig' then
                 assert_equal(config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'], ['$(inherited)', 'FB_SONARKIT_ENABLED=1'])
@@ -144,6 +144,14 @@ def prepare_mocked_installer
                             BuildConfigurationMock.new("Release", is_debug: false),
                             BuildConfigurationMock.new("CustomConfig", is_debug: true),
                         ]
+                    ),
+                    TargetMock.new(
+                        "React-RCTAppDelegate",
+                        [
+                            BuildConfigurationMock.new("Debug", is_debug: true),
+                            BuildConfigurationMock.new("Release", is_debug: false),
+                            BuildConfigurationMock.new("CustomConfig", is_debug: true),
+                        ]
                     )
                 ]
             )

packages/react-native/scripts/cocoapods/flipper.rb

@@ -77,8 +77,8 @@ def flipper_post_install(installer)
             end
         end
 
-        # Enable flipper for React-Core Debug configuration
-        if target.name == 'React-Core'
+        # Enable flipper for React-RCTAppDelegate Debug configuration
+        if target.name == 'React-RCTAppDelegate'
             target.build_configurations.each do |config|
                 if config.debug?
                     config.build_settings['GCC_PREPROCESSOR_DEFINITIONS'] = ['$(inherited)', 'FB_SONARKIT_ENABLED=1']