Merge "Fix 4691563: Polish MultiWaveView experience in LockScreen and InCall...

Merge "Fix 4691563: Polish MultiWaveView experience in LockScreen and InCall screen Better activation experience: 	- Hold off on switching out targets until current animation has finished. 	- Hide unselected targets when a target is selected. Code simplification: 	- Use explicit callback objects to handle animation updates instead of having MWV implement the interface.  	- More compact chevron-loading code. 	- Don't use animations for properties that need to change immediately."