Allow AppCompat to work with long-press-back-menu gesture

Certain OEMs have re-mapped a long-press on the back
button to the menu button. AppCompat will currently
show the options menu and instantly dismiss it. This
CL adds supports so that it isn't dismissed if it was
opened from a long-press of the back button.

BUG: 25582858
Change-Id: I69c4160c03349dfae716430c87aeca5c91aa0453
1 file changed