Currently the code assumes that the user always has a pin or
password or pattern. If there's no password confirmKeyGuard() will
return false, so the acttivity will finish without doing anything.
With this change if there's no PIN/password/pattern, the credential
clearing task will be launched straightaway as the user presses "OK"
the confirmation prompt.
Bug: 127697771
Test: manual
Change-Id: Iac4af0abfc7430ed197e04f833bf203c3f66f52e
Additional clean-up work related to removal of screenlock dependency
from the credentials installation flow:
* Move the CredentialStorage class to security/ so that Enterprise team
owners could review changes to it.
* Remove the ConfigureKeyGuardDialog class as it is no longer used.
* Remove attempt to unlock KeyStore from VPN settings.
* Remove intents that will no longer be sent from the manifest.
Bug: 120901345
Test: m -j RunSettingsRoboTests
Test: Manual with CtsVerifier
Change-Id: Ia708ede3366892d74c148f3712a63858d5ab53b7
