[flexiglass] Fixes failing test after coroutine lib upgrade.

The changed test case started failing after the coroutines library has
been upgraded; not sure why.

This fixes it by toggling the isUnlocked state to trigger the flow under
test to update (since updating getAuthenticationMethod() or
isLockscreenEnabled does not trigger this flow to update).

Bug: 292807808
Test: N/A
Change-Id: Ie26c407931e52a98235c575adf9ba12186caa3a2