Use consistent helper class for keystore authorization

Currently the IKeystoreAuthorization service is intended to be accessed
through the helper class android.security.Authorization.  However,
because Authorization provides only static methods, it can only be
unit-tested by static mocking, which is only available in
mockingservicestests.  BiometricService works around this in two
different ways: (a) using IKeystoreAuthorization directly, and (b) using
android.security.KeyStore, which is an obsolete class which is now
almost empty and just contains a couple random helpers.  I'd like to
remove it to avoid confusion with java.security.KeyStore.

This CL solves the testability problem in a consistent way by renaming
Authorization to KeyStoreAuthorization and changing all public static
methods to instance methods.  It updates all callers of the keystore
authorization service to go through a KeyStoreAuthorization instance.
Finally, it updates the unit tests for TrustManagerService and
BiometricService to inject a mock KeyStoreAuthorization.

Bug: 326508120
Test: atest TrustManagerServiceTest
Test: atest FrameworksServicesTests:{BiometricServiceTest,AuthSessionTest}
Test: atest CtsBiometricsTestCases:BiometricSimpleTests
Flag: N/A.  Refactoring with no behavior change intended.
Change-Id: I68504f447b1b880c08a60cf027b13f77a6567ec9