keyGesture: side key single press dismisses power menu

Currently, if the power(global action) menu is on top, the side key
press doesn't dismiss power menu while it still launches the Recents
menu in background. This is counter-intuitive for users.

The fix is that before Recents menu launch, dismiss the top power menu
first.

Note that the crown button only dismisses the power menu without launch
the all app menu since when power menu is on top, crown button works as
HOME button.

Bug: 436954641
Flag: EXEMPT. trival change
Test: Manual
Change-Id: I0befbc1fdcefeae5db2a4db9d0a3448eaf299945