* This will be used in certprovider tests where we would want more than one server and client certs.
* Also, updated existing usages of these certs to point to the new files.
* Also copy over the required certs/key files. This avoids the example gomodule from depending on gRPC testdata package which should be able to change independently.
* Fix interop test's SAN.
If *grpc.PerRPCCredsCallOption is not found in the option array then change credentialConfigStatus to true and break from the loop. No need to iterate further.
Hrishi Hiraskar
Easwar Swaminathan
Achyuta Das
Michael Le
lyuxuan