Fixes PiP transition with autoEnterPip in button nav

When in button navigation mode with autoEnterPip enabled, we still need
to resume the top focuses activities when tapping on home.

Video: http://rcll/aaaaaabFQoRHlzixHdtY/fys1jBNOQATN62K4DltfHU
Bug: 179498534
Test: enter PiP in button navigation mode with autoEnterPip on,
      see also the video
Change-Id: I896c2bfeb819969475ba549ffbd64344bc017bc2