feat(adjust): add meta install referrer

[huextrat]

Why

This PR adds support for the Meta (Facebook) install referrer plugin in the react-native-adjust config plugin. The Meta install referrer is required for tracking Facebook ad campaigns and attribution in React Native apps using the Adjust SDK.

Currently, users need to manually add the com.adjust.sdk:adjust-android-meta-referrer:5.4.0 dependency to their Android build.gradle file when they want to track Meta install referrers. This enhancement allows the config plugin to automatically handle this dependency injection when configured.

Reference: https://dev.adjust.com/en/sdk/react-native/plugins/meta-referrer-plugin

How

• Added a new optional metaInstallReferrer boolean parameter to the plugin configuration options
• Modified the addAndroidPackagingOptions function to conditionally include the Meta install referrer dependency (com.adjust.sdk:adjust-android-meta-referrer:5.4.0) when the parameter is enabled
• Updated TypeScript type definitions to include the new parameter alongside the existing targetAndroid12 option
• Enhanced the withGradle function to pass through the new parameter to the dependency injection logic
• Updated README.md with comprehensive documentation including usage examples and a link to the official Adjust documentation
• Maintained backward compatibility - existing configurations continue to work without changes

The implementation follows the existing code patterns and architecture, ensuring consistency with the current plugin structure.

Test Plan

Manual Testing:

1. Basic functionality test:

   {
     "plugins": [
       ["@config-plugins/react-native-adjust", { "metaInstallReferrer": true }]
     ]
   }

   • Run npx expo prebuild --clean
   • Verify that android/app/build.gradle contains the Meta install referrer dependency

2. Combined configuration test:

   {
     "plugins": [
       [
         "@config-plugins/react-native-adjust", 
         { 
           "targetAndroid12": true,
           "metaInstallReferrer": true
         }
       ]
     ]
   }

   • Run npx expo prebuild --clean
   • Verify both the Android 12 permission and Meta dependency are added

3. Backward compatibility test:

   {
     "plugins": ["@config-plugins/react-native-adjust"]
   }

   • Run npx expo prebuild --clean
   • Verify existing functionality works without the Meta dependency

4. Parameter disabled test:

   {
     "plugins": [
       ["@config-plugins/react-native-adjust", { "metaInstallReferrer": false }]
     ]
   }

   • Run npx expo prebuild --clean
   • Verify Meta dependency is not added when explicitly disabled

Expected Results:

• When metaInstallReferrer: true, the generated android/app/build.gradle should contain:

  implementation 'com.adjust.sdk:adjust-android-meta-referrer:5.4.0'

• When the parameter is not set or false, the Meta dependency should not be present
• All existing functionality should remain unchanged
• TypeScript compilation should pass without errors