Change the field description.

Author: Hakan Memisoglu

spec.md

@@ -1738,10 +1738,9 @@ message ListSnapshotsRequest {
   // it is cut.
   string snapshot_id = 4;
 
-  // Secrets necessary for listing snapshots.
-  // This field is OPTIONAL. It can be used to pass secrets
-  // required to access some subset of the snapshots in the
-  // storage backend.
+  // Secrets required by plugin to complete ListSnapshot request.
+  // This field is OPTIONAL. Refer to the `Secrets Requirements`
+  // section on how to use this field.
   map<string, string> secrets = 5 [(csi_secret) = true];
 }