Merge from Widevine repo of http://go/wvgerrit/42064
This adds a unit test to verify that OEMCrypto can load a certificate
with an RSA private key generated using the Carmichael Totient.
bug: 67309725
test: No new failures. This code is part of unit tests only.
Change-Id: I492cf6bcff0ac2d1a838e7aa334c4b2b580ac5c7