[ Cherry-pick of http://ag/16087795 ]
[ Merge of http://go/wvgerrit/136432 ]
Once OTA keybox succeeds, the |needs_keybox_provisioning_| flag is
cleared. Access to the system fallback policy is allowed after
provisioning to check status.
Bug: 203177668
Test: ExoPlayer test
Change-Id: I2d28c896c554cfbc9b008340bb415d4c7fac62f2
(cherry picked from commit cac2dcaa6c)