Firebase Remote Config cache invalidation for consistency across platforms

## What feature would you like to see?

Hi,
Thanks for such a great service!
While I was building the same feature on two platforms (iOS and Android) with FRC, I suddenly founded a difference.
When I update my iOS app version, the FRC cache reset and fetch new values. But android don’t.
Please add FIRRemoteConfigHasDeviceContextChanged function to firebase-android-sdk as well.

## How would you use it?

I can setup a FRC condition that depends on the app version. So, when I update my app version, the FRC cache should reset and fetch new values.