Only run face auth onBouncerShowingSoon

When the scene container is not enabled,
only run face auth onBouncerShowingSoon
instead of both onBouncerShowingSoon AND
onBouncerShowing. onBouncerShowingSoon
is always called before onBouncerShowing

If the scene container is enabled,
we run face auth when the scene is
in transition to the bouncer.

Test: atest DeviceEntryFaceAuthInteractorTest
Fixes: 414045086
Flag: EXEMPT bugfix
Change-Id: I0cbe8513582df9ab76bd47f815ea88c2b9145f5a