Add the remaining locksettings unit tests to presubmit

The locksettings unit tests are fast to run, and most of them were part
of presubmit already, so add the remaining ones to presubmit too.

For consistency, also add @SmallTest and @RunWith(AndroidJUnit4.class)
to tests that lacked them.

(This CL does not consider the recoverablekeystore directory.)

Test: atest com.android.server.locksettings
Change-Id: I301e7fd6f5ac8f9e7e3db1a333c68f67abf8bfc3