Updating TrustManagerService to react to keyguard visible changes.

Trustagents should know to downgrade to trustable when the keyguard
visiblity changes. This will fix a bug on tablet where hitting the power
button doesn't sleep the device, and consequently doesn't broadcast the
SCREEN_OFF broadcast which causes the unit tests to fail. This also
fixes a larger issue where if the phone gets unlatched, or if a
trustagent is set up while the phone is unlocked, the phone will be able
to downgrade the trustagent to trustable at the correct time.

As part of this chance, we can remove the USER_PRESENT broadcast which
ends up duplicating the reportKeyguardShowingChanged. Also, in
TemporaryAndRenewableTrustTest.kt, we now grantTrust after waking the
phone which is more realistic and was causing the tests to fail before.

Test: atest TrustTests:TemporaryAndRenewableTrustTests --iterations
Bug: 213631682
Fixes: 231326751
Change-Id: I10a3270ff0b9f12d62acd448ad754f829d843b0e