There were several enum types that all were used for key systems. This
combines them into one to make it more clear and only needing to update
one. This also uses a bit field to specify multiple key systems instead
of using a std::vector.
Change-Id: Ia88039835492a5bd47f449ba4b76187046deeec0
This is in preparation of supporting entitlement license API, where
common encryption server may return concatenated PSSHs directly.
Refactored ProtectionSystemSpecificInfo into a struct containing
concatenated PSSHs. This will make it easier to pass PSSHs around.
Also, most of the time, users of ProtectionSystemSpecificInfo do
not care what is in PSSH; so moved PSSH box parsing and building out
of ProtectionSystemSpecificInfo.
b/78171767
Change-Id: I1c4d5e7e23efd2f7d4b2b9704378323112e47f00