Replace most GoogleMap() rememberUpdatedState() usages with single State object and encapsulate Subcomposition functionality

The GoogleMap() implementation uses a gazillion individual rememberUpdatedState() calls. This is unwieldy and likely contributed to #481.

Instead, a single State object encapsulating the individual state properties can be used and passed as a parameter. This pattern is in compliance with Google Compose API guidelines.

The subcomposition should be made a separate composable function to prevent accidental access to local variables and better encapsulate subcomposition functionality.