Ignore mKeyguardGoingAway if device is not interactive

This was caused by changing where mKeyguardGoingAway was set. This is
a quick/easy way to fix and should be ok/robust enough for now. The better
way would be to update the variable when the animation ends, but that's
trickier.

Fixes: 127577820

Test: Wait for screen to turn off by itself
      Touch fingerprint sensor - device should wake/unlock

Change-Id: If73249aaa749d814669deee55f6044b0e7e2ff5e