Note - there is no GoogleComputEngineSecurityGroupExtensionExpectTest,
due to it being more or less redundant given that we're not making any
new API calls.
Does not include aggregated list method calls, due to those calls not
working with service accounts.
Does not include image insert or deprecate due to the extremely
complex system for creating images in GCE, which makes writing tests
for that a pain. Will come in a later commit.