[SDK] [Flutter] Release FCM v1.0.3

Changelog:

  • Update to WonderPush Android SDK FCM module v1.0.3:
    • Upgrade firebase-messaging to get rid of a dependency on pre-AndroidX support libraries. Without this change you needed to use android.enableJetifier=true.
    • Upgrade firebase-messaging to be compatible with versions 22+, as they replaced their Instance ID SDK with their Installations SDK.
      WonderPush failed to retrieve a push token with such versions of the dependency. This only affected users that depended on Firebase outside of WonderPush if one of their dependencies forced the firebase-messaging to use version 22+.