Reset primary bouncer face message to default when face auth restarts

Only reset the primary bouncer message on face auth
restarting if the currently shown message was a face message.
We don't want to reset fingerprint messages.

Also, we don't reset fingerprint messages when
a new fingerprint auth begins; since fingerprint
is much faster, the messages may look flickery
if the message was rest each time fingerprint
is re-tried.

Test: atest BouncerMessageInteractorTest
Test: Authenticate from primary bouncer with a mask, see
mask covering message. Restart face auth on the bouncer
and observe the mask covering message is reset.
Fixes: 330248002
Flag: EXEMPT bugfix

Change-Id: I19e981f4c5226e4f3be7a30bef70ad09ace1da0d