Decouple superuser from SessionMetadata

Superuser should only be settable via the tool (see []
which is merged in here but not diffbased, and which removes
the implicit superuser for CharlestonRoad). It is a property
of the request, not of the session (there are no sessions in the tool).
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125204707

java/google/registry/flows/EppRequestHandler.java

@@ -43,11 +43,12 @@ public class EppRequestHandler {
       SessionMetadata sessionMetadata,
       TransportCredentials credentials,
       boolean isDryRun,
+      boolean isSuperuser,
       byte[] inputXmlBytes) {
     try {
       response.setPayload(new String(
           eppController.handleEppCommand(
-              sessionMetadata, credentials, isDryRun, inputXmlBytes), UTF_8));
+              sessionMetadata, credentials, isDryRun, isSuperuser, inputXmlBytes), UTF_8));
       response.setContentType(APPLICATION_EPP_XML);
       // Note that we always return 200 (OK) even if the EppController returns an error response.
       // This is because returning an non-OK HTTP status code will cause the proxy server to