Fix face enroll introduction crash after 10mins

When requestGatekeeperHat() throws exception in FaceEnrollIntroduction
page, remove gk_pw_handle and recreate activity to trigger confirmLock.

Test: robotest for FaceEnrollIntroductionTest
Bug: 234437174
Change-Id: Ie1dd6f36e4deb3f776e3b39acd165fc47d04f526
Merged-In: Ie1dd6f36e4deb3f776e3b39acd165fc47d04f526
3 files changed