Register ProjectDeletion events for gson serialization

ProjectDeletion events were not registered event types.

This caused failures when EventGson tried to serialize/deserialize
objects having those events as field, Throwing the JsonParseException:

```
Unknown event type: project-deletion-replication-scheduled
```

Register ProjectDeletion event types, similarly to what already done for
Ref replication events (RefReplicatedEvent, RefReplicationDoneEvent,
RefReplicationScheduledEvent).

This change cherry-picks change [1]

[1]https://gerrit-review.googlesource.com/c/plugins/replication/+/308383

Bug: Issue 14628
Change-Id: I7471e9a0f8ea8ec27d5800f785d1c7006b35055c
6 files changed
tree: 65964c503f3f9c23088fcabff02f7fb938fba398
  1. .settings/
  2. src/
  3. .gitignore
  4. .mailmap
  5. BUILD
  6. LICENSE