Revert "grpc: explicitly prevent Retry until we're ready for it"

This reverts commit 625cd1887957946515db468ce519bb71fa31fc7f.

Reason for revert: this CL is fine, but we're currently testing some grpc-go problems that involve the user using old versions of grpc-go. The option added in this CL is not supported in older versions of grpc-go, so it becomes a nuisance for users that are trying to pin to old grpc-go versions.

Change-Id: I69118e9aef12c99822cbddb8aa4546e3237dada1
Reviewed-on: https://code-review.googlesource.com/c/34290
Reviewed-by: David Symonds <dsymonds@golang.org>
diff --git a/transport/grpc/dial.go b/transport/grpc/dial.go
index e14f492..c79b835 100644
--- a/transport/grpc/dial.go
+++ b/transport/grpc/dial.go
@@ -59,9 +59,7 @@
 	if o.GRPCConn != nil {
 		return o.GRPCConn, nil
 	}
-	grpcOpts := []grpc.DialOption{
-		grpc.WithDisableRetry(), // We don't want to have two methods of retry until we're ready for it.
-	}
+	var grpcOpts []grpc.DialOption
 	if insecure {
 		grpcOpts = []grpc.DialOption{grpc.WithInsecure()}
 	} else if !o.NoAuth {