Merge of https://widevine-internal-review.googlesource.com/#/c/8263
from the Widevine repo.
Changes the behavior of requiresSecureDecoderComponent() to query the
session for whether a lowered security level has been requested
before querying the system to see what its default security level is.
As part of this, we added a new QuerySessionStatus() method to the
CDM that gets status info on a session-specific level, such as the
effective security level of a session.
Bug: 11428937
Change-Id: I5549a2fdd400cc87f567d27fcf74c473451093d6
fd482527e4