* 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.
Google default creds is a combo of ALTS, TLS and OAuth2. The right set of creds will be picked to use based on environment.
This PR contains:
- A new `creds.Bundle` type
- changes to use it in ClientConn and transport
- dial option to set the bundle for a ClientConn
- balancer options and NewSubConnOption to set it for SubConn
- Google default creds implementation by @cesarghali
- grpclb changes to use different creds mode for different servers
- interop client changes for google default creds testing
Doug Fawley
Easwar Swaminathan
Gaurav Gahlot
Zou Nengren
DO ANH TUAN
Menghan Li