[ Merge of http://go/wvgerrit/160277 ]
OEMCrypto v15 did not require core messages during DRM certificate
provisioning. The CDM's certificate provisioning flow was allowing
for either case (with or without core messages) when provisioning.
Now, devices can safely assume that all provsisioning responses will
be v16 or newer; all requests/response must contain a core message.
Bug: 252670759
Test: run_x86_64_tests and request_license_test
Change-Id: I9f51e07caf642eaf646ef40bdd640b3ccfe2533c
6b9aa2c12d