base: added camera flip activation for n1

Flipping camera will start camera app
both from offscreen and onscreen

This also adds a property that can force enable
DEBUG_INPUT since this can be extremely helpful
to enable without rebuilding

Activate with
config.override_debugInput=1

Change-Id: I3e67e5dc3df8b4d4f89daa6a8aad475f3794a37b
Merge pull request #3 from omnirom/android-4.4

base: added camera flip activation for n1