Update co-ex error logic

KeyguardIndication (bottom text area on LS)
- show transient messages for a minimum of 2000ms not including animation
time
- if dual auth is enrolled: only show face auth errors if the user
explicitly requested face auth

In general, don't request face auth on the global actions menu
(likely left over from when the power menu had affordances for
components requiring authentication)

Test: atest SystemUITest
Fixes: 186302245
Bug: 183698582
Change-Id: I0290c66addc9981bf3fe20de24110e2d35e1f8eb