Add new values to KeyRequestType

Two additional KeyRequestTypes have been added, None and Update. None
indicates that no key request is needed as keys have already been
loaded. Update indicates that while keys have previously been loaded,
an additional (non-renewal) license request is needed.

Bug: 70335058
Test: GtsMediaTestCases
Change-Id: I36a8b334c70140098a01e4a3bea3159fc0a4584f