Fix back button on fragments without help uris

This is a follow up to 0708d9e119. The setHasOptionsMenu has
to be set for the back button to work and this needs to happen
regardles if the fragment has an help uri or not.

Bug: 28237921
Change-Id: Icec7a94312bdab5470efa0893a339d753c995eb1
1 file changed