DO NOT MERGE Make labels view have grey app bar

Bug: 31268067

Test: manual
  - navigate b/w fragments + rotate screen
  - create a new label and delete a label
  - enter/exit edit mode of group fragment and contacts fragment

Change-Id: Ie4bc38456dae8840df3ae511c2fbbd0d336038bc
(cherry picked from commit 3dd13761f1c2c615004af129afa5ebc56efe8ada)