Update plugin.xml for 1.1.0

[DiogoMadeiraOS]

Added Messaging Event service to OSFirebaseCloudMessaging

Description

Context

Type of changes

• Fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Refactor (cosmetic changes)
• Breaking change (change that would cause existing functionality to not work as expected)

Platforms affected

• Android
• iOS
• JavaScript

Tests

Screenshots (if appropriate)

Checklist

• Pull request title follows the format RNMT-XXXX <title>
• Code follows code style of this project
• CHANGELOG.md file is correctly updated
• Changes require an update to the documentation
  • Documentation has been updated accordingly