Cleans up fragments when removed

 Bug: 3198097
 This change fixes it so that when the Combined view is removed,
 it also removes any added fragments. This fixes the issue where
 "Clear History" menu option would still be displayed after leaving
 the history view.

Change-Id: I7ff995d856ef21be1900f90ece2efaf3d4e19f8b
1 file changed