Add unit test coverage for unlock attempts in TrustTests

The downstream effects of an unlock attempt using a pin/password were
not previously tested within the TrustTests. Add these tests in
preparation for further changes to pin/password unlock reporting to
TrustManagerService.

Add options within ScreenLockRule and TrustAgentRule to allow for test
cases to start with strong auth being required, and the device locked.

BUG: b/323086607
Test: `atest TrustTests`
Flag: TEST_ONLY
Change-Id: I1c8eaacc9c20284ef2783bcd65c14f68b0b444e8