Use precompipled binaries by default (#54895)

Summary:
This change set up React native to use the precompiled binaries by default.
Users can still turn them off by passing `RCT_USE_PREBUILT_RNCORE=0 bundle exec pod install`

By default, RNTester will still build from source.

## Changelog:
[iOS][Changed] - Use prebuild by default

Pull Request resolved: #54895

Test Plan: Tested on a React native app created using RN 0.83.0

Reviewed By: huntie

Differential Revision: D89277683

Pulled By: cipolleschi

fbshipit-source-id: 4781e9e5561c3c7b264d2b1547910c9b4f63c276

Author: cipolleschi

packages/react-native/scripts/react_native_pods.rb

@@ -84,6 +84,11 @@ def use_react_native! (
   # This is needed as part of our migration away from cocoapods
   ENV['RCT_SKIP_CODEGEN'] = ENV['RCT_SKIP_CODEGEN'] == '1' || ENV['RCT_IGNORE_PODS_DEPRECATION'] == '1' ? '1' : '0'
 
+  # Use the React Native precompiled binaries by default.
+  # Users can still turn them off and build from source by setting the environment variable to 0.
+  ENV['RCT_USE_RN_DEP'] = ENV['RCT_USE_RN_DEP'] == '0' ? '0' : '1'
+  ENV['RCT_USE_PREBUILT_RNCORE'] = ENV['RCT_USE_PREBUILT_RNCORE'] == '0' ? '0' : '1'
+
   ReactNativePodsUtils.check_minimum_required_xcode()
 
   # Current target definition is provided by Cocoapods and it refers to the target