Implement PiP custom close action on phone

To use this new custom close action on Phone
- We expect app providing actions via
  PictureInPictureParams.Builder#setActions as they normally do
- We also expect app providing a custom close action via
  PictureInPictureParams.Builder#setCloseAction
- The custom close action is used on Phone only if it matches one of the
  actions listed in setActions (by comparing the PendingIntent)

SysUI will render the custom close action with a highlighted background
and ensures the PiP dismisses after certain timeout if the app fails to
respond in time.

Video: http://recall/-/aaaaaabFQoRHlzixHdtY/fR0hxeorlYrxXyzfZ02btK
Bug: 223896879
Test: see video
Change-Id: I65c585ae3224061311e476753bc4c72f00c4fa33