[2/2] base: overflow menu tweaks

Combines two features:

1) for devices with a hw keys support force show the
3dot overflow menu in applications. This allows remapping
of the menu key to other actions and/or better support devices that
have hw keys but no menu key like m7.

2) for devices with soft-keys force hiding the 3dot overflow
menu by emulating existence of a hw menu button and only
showing a navbar soft menu key

PS5
set default of force overflow to 1 if this is a device
with hw keys but without menu key e.g. m7

PS6
checking config_deviceHardwareKeys is not enough

PS7
too stupid

Change-Id: Ic7a7e4bde440cee0e274e6ea871c952998a56dd7
Merge "[2/2] base: overflow menu tweaks" into android-4.4