Remove unnecessary getAuthenticatorId

The framework already caches the authenticatorId upon user
switches and new enrollments. So, if the requested user is already
the current user, there should be no need to request the HAL for
the authenticatorId.

Bug: 178018968
Test: manual
Change-Id: I6965605b16a4334324c53ed110ca92c2cec46bad
1 file changed