Create a separate billing event when EAP is applied

When EAP is involed we current have one billing event for domain create that
has the create fee and EAP fee lumped together. Change it to record two
separate billing events for each.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132335349

java/google/registry/model/billing/BillingEvent.java

@@ -71,6 +71,7 @@ public abstract class BillingEvent extends ImmutableObject
     ALLOCATION,
     ANCHOR_TENANT,
     AUTO_RENEW,
+    EAP,
     LANDRUSH,
     SUNRISE,
     /**