Add Ad Click Event Callback for Rewarded Video Ads to capture if the user click on the rewarded video ads.

Currently, the @capacitor-community/admob plugin does not provide an event callback for when a user clicks on a rewarded video ad. This feature would be helpful for tracking ad engagement and improving analytics.

when we need to track ad clicks for rewarded video ads to analyze user interaction.
Some use cases involve rewarding users based on engagement, tracking analytics, or logging events for optimization.
Native AdMob SDKs provide ad click events, but this functionality is missing in the Capacitor plugin.

No file or test is named. Start by locating the rewarded video event handling and the Capacitor bridge to the native AdMob SDK, then compare the available native ad callbacks. Done means a rewarded-video click callback is exposed by the plugin and can be used for engagement tracking, with coverage for the new event.

Written by the indexing model from the issue text.