SLRP failed to connect to CSI endpoint.

After bumping the gRPC bundle to 1.8.3, there are some flakiness in SLRP tests caused by SLRP not being able to connect to a CSI endpoint. The reason is that it seems to take longer for gRPC 1.8 to prepare a domain socket (i.e., the time between the bind and accept calls are longer), and as a result, SLRP cannot talk to a CSI plugin immediately after the socket file is created.