This is a merge of
https://widevine-internal-review.googlesource.com/c/cdm/+/144790
Updated cipher mode to allow playback in v17;
Added check for key selection before decrypting.
Merge from Widevine repo of http://go/wvgerrit/144779
Fix allow_null for key control iv in L3 v17
Merge from Widevine repo of http://go/wvgerrit/144792
Fix api version check in L3 v17
Test: L3 unit tests
Bug: 217145027
Change-Id: I584bd57e26407cbf4d4b94eb1bc5cf80839377be
(cherry picked from commit efbe13ea36)
Merged-In:I584bd57e26407cbf4d4b94eb1bc5cf80839377be