NBV: pass string[] to keybuttoninfo instead of overloading constructors

this way is a lot more flexible and will allow easier upstream additions that will have
a lot more arguments to pass

PS2: fix derp in previous patchset that was supposed to call loadbuttonarrays instead of
setupNavigationButtons(getCurrentButtonArray())

Change-Id: Id870ab823409afc740f78a2598d68e3de93b8c46