ChangeBundle: Don't implement hashCode/equals

Due to timestamp rounding, equals is no longer transitive, since
ReviewDb bundles must match exactly but different ones might round to
different NoteDb values. We never put these in collections or compare
them except by using differencesFrom directly, so just delete these
methods.

Change-Id: I4aacb404dc73f64fdd31061710629cbe6009d7fa

gerrit-server/src/main/java/com/google/gerrit/server/notedb/ChangeBundle.java

@@ -476,24 +476,6 @@ public class ChangeBundle {
     return normalized;
   }
 
-  @Override
-  public boolean equals(Object o) {
-    if (!(o instanceof ChangeBundle)) {
-      return false;
-    }
-    return differencesFrom((ChangeBundle) o).isEmpty();
-  }
-
-  @Override
-  public int hashCode() {
-    return Objects.hash(
-        change.getId(),
-        normalizeChangeMessages(),
-        patchSets.keySet(),
-        patchSetApprovals.keySet(),
-        patchLineComments.keySet());
-  }
-
   @Override
   public String toString() {
     return getClass().getSimpleName() + "{id=" + change.getId()