Smoothen Flipper iOS integration (#28044)

Summary:
Addresses my feedback [here](https://github.com/facebook/react-native/issues/27565#issuecomment-580950480), [here](https://github.com/facebook/react-native/issues/27565#issuecomment-582490074), and [here](https://github.com/facebook/react-native/issues/27565#issuecomment-585456768).

## Changelog

[iOS] [Changed] - Updated Flipper iOS integration to be included by default in the `Debug` configuration
Pull Request resolved: https://github.com/facebook/react-native/pull/28044

Test Plan:
Manually tested that a new application from this template still works and that the Flipper integration works.

<img width="912" alt="Screenshot 2020-02-13 at 02 09 42" src="https://user-images.githubusercontent.com/2320/74391951-eb6fd800-4e05-11ea-9fde-7e0eb42c1ec4.png">

Differential Revision: D19871482

Pulled By: TheSavior

fbshipit-source-id: a805808fdd0c2dfdfe47dd59ffee02c81f3fdfa7

scripts/autolink-ios.rb

@@ -4,7 +4,6 @@
 # LICENSE file in the root directory of this source tree.
 
 def use_react_native! (options={})
-
   # The prefix to the react-native
   prefix = options[:path] ||= "../node_modules/react-native"
 
@@ -56,5 +55,24 @@ def use_react_native! (options={})
     pod 'React-RCTFabric', :path => "#{prefix}/React"
     pod 'Folly/Fabric', :podspec => "#{prefix}/third-party-podspecs/Folly.podspec"
   end
-
 end
+
+def add_flipper_pods!
+  version = '~> 0.30.0'
+  pod 'FlipperKit', version, :configuration => 'Debug'
+  pod 'FlipperKit/FlipperKitLayoutPlugin', version, :configuration => 'Debug'
+  pod 'FlipperKit/SKIOSNetworkPlugin', version, :configuration => 'Debug'
+  pod 'FlipperKit/FlipperKitUserDefaultsPlugin', version, :configuration => 'Debug'
+  pod 'FlipperKit/FlipperKitReactPlugin', version, :configuration => 'Debug'
+end
+
+# Post Install processing for Flipper
+def flipper_post_install(installer)
+  installer.pods_project.targets.each do |target|
+    if target.name == 'YogaKit'
+      target.build_configurations.each do |config|
+        config.build_settings['SWIFT_VERSION'] = '4.1'
+      end
+    end
+  end
+end