Support 3D follow

**Is your feature request related to a problem? Please describe.**

It would be nice to have a feature in the library that developers can turn on or off that would have the map camera automatically follow the user's location on the map in 3D - something like this:


**Describe the solution you'd like**

Moving and tilting the map camera based on rotation vector sensors is described in this Google I/O video (including sample code), which the above screenshot is grabbed from:
https://youtu.be/_oZiK_NJuG8?t=1453

I've implemented a version of this in an app I maintain:
https://github.com/barbeau/gpstest/blob/master/GPSTest/src/google/java/com/android/gpstest/GpsMapFragment.java#L281

Exact API design is TBD.

**Describe alternatives you've considered**
Do nothing - don't implement the feature

**Additional context**
See links above