(This is a merge of http://go/wvgerrit/97083.)
The switch from LoadKeys to LoadLicense broke entitlement licenses
entirely because the LoadLicense path in CryptoSession didn't include
any affordances for updating the KeySession, unlike the LoadKeys path.
This patch adds code to handle this.
Bug: 152814106
Test: CE CDM Unit Tests
Test: Android Unit Tests
Change-Id: Id0c33a566e17e6be8da04e12be4b0fc87559aa8f