Merge from Widevine repo of http://go/wvgerrit/154874 We do not require an error to come from SelectKey immediately, it can come from a following call to DecryptCENC. This adds a function Session::TestDecryptCENC to be called instead of SelectKey for the tests that use entitled sessions. Bug: 232225906 Test: tested with http://go/ag/20420224 Change-Id: If5695a5034cce371b6eb6bcf1b6467d84456c21d