Fix up back press with bubbles manage menu or user education

If manage menu is open or user education for the manage
menu is showing, hitting back would close the whole bubble.
Instead it should just close the manage menu, or the user
education view.

Also fixed a couple of cases where user education should
animate away.

Test: manual - hit back while manage menu or manage menu
               user education is open, the bubble should
               stay open & the menu should hide.
             - hit back while stack education is open &
	       check that back works normally after it
	       goes away
Bug: 195556909
Change-Id: I60f2bedbf5dd45847139c4e89c900ee7cc54318f