Populate the contact in ContactHistory objects created in Contact flows (#1111)

* Populate the contact in ContactHistory objects created in Contact flows

Minimal interesting changes here
- a bit of reconstruction in ContactHistory to get the repo ID from the
key
- making the History revision ID Long instead of long so that it can be
null in non-built intermediate entities
- adding a copyFrom(HistoryEntry.Builder) method in HistoryEntry.Builder
so that we don't need to allocate quite as many unnecessary IDs, i.e.
removing the .build() lines in provideContactHistory and
provideDomainHistory

core/src/test/java/google/registry/flows/ResourceFlowTestCase.java

@@ -193,7 +193,10 @@ public abstract class ResourceFlowTestCase<F extends Flow, R extends EppResource
       HistoryEntry historyEntry = Iterables.getLast(DatabaseHelper.getHistoryEntries(resource));
       if (resource instanceof ContactBase) {
         ContactHistory contactHistory = (ContactHistory) historyEntry;
-        assertThat(contactHistory.getContactBase().get()).isEqualTo(resource);
+        // Don't use direct equals comparison since one might be a subclass of the other
+        assertAboutImmutableObjects()
+            .that(contactHistory.getContactBase().get())
+            .isEqualExceptFields(resource);
       } else if (resource instanceof DomainContent) {
         DomainHistory domainHistory = (DomainHistory) historyEntry;
         assertAboutImmutableObjects()

core/src/test/java/google/registry/flows/contact/ContactCreateFlowTest.java

@@ -56,14 +56,13 @@ class ContactCreateFlowTest extends ResourceFlowTestCase<ContactCreateFlow, Cont
     assertTransactionalFlow(true);
     runFlowAssertResponse(loadFile("contact_create_response.xml"));
     // Check that the contact was created and persisted with a history entry.
-    assertAboutContacts()
-        .that(reloadResourceByForeignKey())
-        .hasOnlyOneHistoryEntryWhich()
-        .hasNoXml();
+    ContactResource contact = reloadResourceByForeignKey();
+    assertAboutContacts().that(contact).hasOnlyOneHistoryEntryWhich().hasNoXml();
     assertNoBillingEvents();
     if (tm().isOfy()) {
-      assertEppResourceIndexEntityFor(reloadResourceByForeignKey());
+      assertEppResourceIndexEntityFor(contact);
     }
+    assertLastHistoryContainsResource(contact);
   }
 
   @TestOfyAndSql

core/src/test/java/google/registry/flows/contact/ContactDeleteFlowTest.java

@@ -78,6 +78,7 @@ class ContactDeleteFlowTest extends ResourceFlowTestCase<ContactDeleteFlow, Cont
         .hasOnlyOneHistoryEntryWhich()
         .hasType(HistoryEntry.Type.CONTACT_PENDING_DELETE);
     assertNoBillingEvents();
+    assertLastHistoryContainsResource(deletedContact);
   }
 
   @TestOfyAndSql

core/src/test/java/google/registry/flows/contact/ContactTransferApproveFlowTest.java

@@ -120,6 +120,7 @@ class ContactTransferApproveFlowTest
     assertThat(panData.getTrid())
         .isEqualTo(Trid.create("transferClient-trid", "transferServer-trid"));
     assertThat(panData.getActionResult()).isTrue();
+    assertLastHistoryContainsResource(contact);
   }
 
   private void doFailingTest(String commandFilename) throws Exception {

core/src/test/java/google/registry/flows/contact/ContactTransferCancelFlowTest.java

@@ -104,6 +104,7 @@ class ContactTransferCancelFlowTest
                 .collect(onlyElement())
                 .getTransferStatus())
         .isEqualTo(TransferStatus.CLIENT_CANCELLED);
+    assertLastHistoryContainsResource(contact);
   }
 
   private void doFailingTest(String commandFilename) throws Exception {

core/src/test/java/google/registry/flows/contact/ContactTransferRejectFlowTest.java

@@ -119,6 +119,7 @@ class ContactTransferRejectFlowTest
         .isEqualTo(Trid.create("transferClient-trid", "transferServer-trid"));
     assertThat(panData.getActionResult()).isFalse();
     assertNoBillingEvents();
+    assertLastHistoryContainsResource(contact);
   }
 
   private void doFailingTest(String commandFilename) throws Exception {

core/src/test/java/google/registry/flows/contact/ContactTransferRequestFlowTest.java

@@ -137,6 +137,7 @@ class ContactTransferRequestFlowTest
         Iterables.filter(
             loadByKeys(contact.getTransferData().getServerApproveEntities()), PollMessage.class),
         ImmutableList.of(gainingApproveMessage, losingApproveMessage));
+    assertLastHistoryContainsResource(contact);
   }
 
   private void doFailingTest(String commandFilename) throws Exception {

core/src/test/java/google/registry/flows/contact/ContactUpdateFlowTest.java

@@ -64,12 +64,16 @@ class ContactUpdateFlowTest extends ResourceFlowTestCase<ContactUpdateFlow, Cont
     clock.advanceOneMilli();
     assertTransactionalFlow(true);
     runFlowAssertResponse(loadFile("generic_success_response.xml"));
+    ContactResource contact = reloadResourceByForeignKey();
     // Check that the contact was updated. This value came from the xml.
-    assertAboutContacts().that(reloadResourceByForeignKey())
-        .hasAuthInfoPwd("2fooBAR").and()
+    assertAboutContacts()
+        .that(contact)
+        .hasAuthInfoPwd("2fooBAR")
+        .and()
         .hasOnlyOneHistoryEntryWhich()
         .hasNoXml();
     assertNoBillingEvents();
+    assertLastHistoryContainsResource(contact);
   }
 
   @TestOfyAndSql