Update certificates used by grpc automated tests

**Describe the bug**
Certs used by grpc tests have been expired on Oct 26th

**To Reproduce**
Run grpc automated tests, fails with:
```
failed to connect to all addresses; last error: UNKNOWN: ipv4:172.18.0.2:31139: Ssl handshake failed: SSL_ERROR_SSL: error:1000007d:SSL routines:OPENSSL_internal:CERTIFICATE_VERIFY_FAILED
```

**Expected behavior**
Should pass
