Config RubyGems Bundler in setup script

- add to 'setup' script (DevEx, iOS CI)
- skip RubyGems Bundler config on Ubuntu

Ref: react-native-community/template#209

Author: leotm

.github/workflows/android.yml

@@ -42,7 +42,7 @@ jobs:
 #       node_modules cache
 
     - name: Install deps and setup
-      run: yarn && yarn setup
+      run: yarn && yarn allow-scripts # no need to 'setup' RubyGems Bundler config
 
     - name: npx react-native info
       run: npx react-native info

package.json

@@ -3,7 +3,7 @@
   "version": "0.0.1",
   "private": true,
   "scripts": {
-    "setup": "allow-scripts",
+    "setup": "allow-scripts && yarn setup:gems",
     "setup:gems": "bundle config set --local path 'vendor/bundle' && bundle config set --local force_ruby_platform true",
     "allow:auto": "allow-scripts auto",
     "start": "react-native start",