Cuttlefish: use random root key for RKP

All cuttlefish instances were using the same root key for remote key
provisioning. This is because CF is currently using the pure soft remote
provisioning context.

To allow for safer RKP testing (e.g. allowing uploads of CF keys to the
device info service), change the pure soft remote provisioning context
so that every instance gets a random key.

Test: VtsHalRemotelyProvisionedComponentTargetTest
Change-Id: I730a6c4596177a2d872fc573cf39d0c6ac8f3ba8
1 file changed