add recent apps GB style action to navbar buttons (2/2)

This will add the option to open the Gingerbread style
recent application dialog.
This is the dialog that will show when doing <Alt><Tab> with
a bluetooth keyboard.

Change-Id: If396c4b440d9b0a6a69cec22d81d418c7ea8ce3d
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>

Conflicts:
	res/values/arrays.xml
	res/values/strings.xml