Fix: CTS Verifier app crashes Fingerprint Bound keys Test

The CTS Verifier app crashes due to using a non static
member class as fragment. It is impossible to recover the
state of the fragment upon configuration change. This was
never a problem for the Fingerprint Bound Keys Test because
it handles configuration changes and is not recreated.
However, as of SDK version N_MR1 a check was introduced
that checks the condition before it leads to problems
causing this crash.

This patch makes the FingerprintAuthDialogFragment a static
member class to fix the issue.

Bug: 63066872
Test: Install and run CtsVerifier then perform the
      "Fingerprint Bound Keys Test"

Change-Id: I530978b8bb9790ae404c342317284c4766082bbd
(cherry picked from commit b15813d813c95c87e04956badf81d3b02de60d15)
1 file changed