Merge from the widevine repo of http://go/wvgerrit/16362
A test class holds a default session that it expects to be able to
close in the tear down. This was not true in the TimingTest because
it calls OEMCrypto_Terminate which closes all open sessions.
This CL closes the default session, and then reopens it again after
OEMCrypto_Initialize.
Change-Id: Ib4128ec3c0a33794c03aa934174cb6fff448483e
4a37b21a22