Merge from Widevine repo of http://go/wvgerrit/14973 and
http://go/wvgerrit/14573.
Some devices were failing the variable length key id tests, so they
were removed from Android while we decided whether the tests are too
strict for future releases.
This CL re-instates the tests with the understanding that the maximum
key id length is 16 bytes, as discussed in b/24469550. If we decide
that it is OK to have longer key ids, then another CL will be needed
to test with those lengths.
bug: 21935358
Change-Id: Ic6b776a8b119daac961c71280994fcc944984d8a
a9fe9bb38c