Keyguard: give the Keyguard a non-empty app label

A blank app label under "Apps" looks suspicious to
the untrained eye.

Change-Id: Ic679e5d6d825a83a8f666bb7e6429bebf1280f6d
Signed-off-by: Roman Birg <roman@cyngn.com>
(cherry picked from commit 9757a1db0c4e60ce85fe93573c2da62bf3880231)