This is a merge of http://go/wvgerrit/13701 and http://go/wvgerrit/13780.
I added a new set of engine properties for the mock oemcrypto. This
set pretends to be level 1. This allows the widevine build bot to test
the dual security level path: a level 1 liboemcrypto.so and a fall
back to L3.
I also adjusted the failing test in oemcrypto_test.cpp. A correct fix
requires us to rewrite some of the oemcrypto mock code so that it
returns real error codes instead of just 'false' on error.
Change-Id: I9cdbfc23c87ad2fb6068eac1394ce4c5b6a32dae
047f543e7c