Add provider facing CREATE APIs for Credential Manager.

Credential Manager is a set of APIs that allows developers to get and
create credentials. These credentials are sourced from providers that
are registered with the android framework.

Test: Built and Deployed on device locally.
Bug: 247545196
CTS-Coverage-Bug: 247549381

Change-Id: I640259d5c803260740633f489a8bcf3a4168b652