Validate decryption key length to decrypt function.
Cherry picked from http://go/ag/
3038278.
AesCtrDecryptor::decrypt() doesn't check whether the size of "key"
is equal to 16 bytes, which may lead to an OOB read problem in the
context of mediadrmserver.
Add DecryptsWithEmptyKey and DecryptsWithKeyTooLong unit tests.
Test: ClearKeyDrmUnitTest
adb shell LD_LIBRARY_PATH="/vendor/lib/mediadrm"
/data/nativetest/ClearKeyDrmUnitTest/ClearKeyDrmUnitTest
bug:
63982768
Change-Id: I1f22c9df2b051972b2c532608b7f203e3ce77926
(cherry picked from commit
379b672b189aa72ce0103b485019022f3e292c36)