(This is a merge of http://go/wvgerrit/14783) When validation was added to the service certificate property, it broke the associated test, which sends random data. It also did not do any testing of the new validation itself. This fix makes the validation method on WvContentDecryptionModule non-static so that it can be mocked and handled appropriately in the test. Bug: 21923281 Change-Id: Id5d2315709fce35f9347b3545f594371810349f0