Use the actual EPP command flow name for EppMetrics

It was previously only using the name of the inner command XML element,
e.g. "Create", "Delete", "Update", etc. This wasn't very useful because
there was no way to discriminate between operations on different types
of EPP resources.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=151131491

java/google/registry/flows/EppController.java

@@ -85,7 +85,6 @@ public final class EppController {
         metricBuilder.setStatus(e.getResult().getCode());
         return getErrorResponse(e.getResult(), Trid.create(null));
       }
-      metricBuilder.setCommandName(eppInput.getCommandName());
       if (!eppInput.getTargetIds().isEmpty()) {
         metricBuilder.setEppTarget(Joiner.on(',').join(eppInput.getTargetIds()));
       }

java/google/registry/flows/FlowRunner.java

@@ -56,6 +56,7 @@ public class FlowRunner {
   @Inject TransportCredentials credentials;
   @Inject EppRequestSource eppRequestSource;
   @Inject Provider<Flow> flowProvider;
+  @Inject Class<? extends Flow> flowClass;
   @Inject @InputXml byte[] inputXmlBytes;
   @Inject @DryRun boolean isDryRun;
   @Inject @Superuser boolean isSuperuser;
@@ -92,6 +93,7 @@ public class FlowRunner {
             "clientId", clientId,
             "xml", prettyXml,
             "xmlBytes", xmlBase64)));
+    metric.setCommandNameFromFlow(flowClass.getSimpleName());
     if (!isTransactional) {
       metric.incrementAttempts();
       return EppOutput.create(flowProvider.get().run());