Remove more usage of AutoValue (#2432)

This PR also removes `SerializedForm` used to serialize
`PendingDeposit`, as it is now a simple record.

core/src/test/java/google/registry/bsa/BsaDiffCreatorTest.java

@@ -47,11 +47,9 @@ class BsaDiffCreatorTest {
 
   @Mock GcsClient gcsClient;
 
-  @SuppressWarnings("DoNotMockAutoValue")
   @Mock
   DownloadSchedule schedule;
 
-  @SuppressWarnings("DoNotMockAutoValue")
   @Mock
   CompletedJob completedJob;
 

core/src/test/java/google/registry/bsa/persistence/LabelDiffUpdatesTest.java

@@ -60,7 +60,6 @@ class LabelDiffUpdatesTest {
 
   @Mock IdnChecker idnChecker;
 
-  @SuppressWarnings("DoNotMockAutoValue")
   @Mock
   DownloadSchedule schedule;