Remove face to fingerprint multi-sensor behavior.

Refactor existing tests to remove unnecessary mocks and boilerplate code to
cover more of the real behavior. This is prep for adding new tests in another
change to add the new face and fingerprint behavior.

Bug: 217393533
Test: atest AuthBiometricViewTest AuthContainerViewTest
Test: manual (authenticate using test app)

Change-Id: If984d1c07fee98d2d7a20cb0025ad434ad9977f4