Allow bypass + show errors on alt bouncer

- Show the keyguard bouncer errors so users are aware of auth errors
- Also fixes a bug where we wouldn't proceed to the activity (ie:
notification click) if the user authenticated from the alt bouncer
using passive auth. now, the bypass logic includes when the alt bouncer
is showing.

Test: manual
Fixes: 186313318
Fixes: 192355757
Change-Id: I3caffd2e89b9ae596b11ca4a05665db53491c2d2