Move two enums from FlowRunner to FlowTestCase.

They are only needed in test code.
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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=125126550

java/google/registry/flows/Flow.java

@@ -101,14 +101,13 @@ public abstract class Flow {
       EppInput eppInput,
       Trid trid,
       SessionMetadata sessionMetadata,
-      boolean superuser,
       DateTime now,
       byte[] inputXmlBytes) throws EppException {
     this.eppInput = eppInput;
     this.trid = trid;
     this.sessionMetadata = sessionMetadata;
     this.now = now;
-    this.superuser = superuser;
+    this.superuser = sessionMetadata.isSuperuser();
     this.inputXmlBytes = inputXmlBytes;
     initFlow();
     validExtensions = ImmutableSet.copyOf(validExtensions);