Automatic merge from submit-queue (batch tested with PRs 48439, 48440, 48394)

GuaranteedUpdate must write if stored data is not canonical

An optimization added to the GuaranteedUpdate loop changed the
comparison of the current objects serialization against the stored data,
instead comparing to the in memory object, which defeated the mechanism
we use to migrate stored data (GET then PUT should update the version stored in etcd if the canonical serialization has changed)

This commit preserves that optimization but correctly verifies the in
memory serialization against the on disk serialization by fetching the
latest serialized data. Since most updates are not no-ops, this should
not regress the performance of the normal path.

Fixes #48393

```release-note
When performing a GET then PUT, the kube-apiserver must write the canonical representation of the object to etcd if the current value does not match. That allows external agents to migrate content in etcd from one API version to another, across different storage types, or across varying encryption levels. This fixes a bug introduced in 1.5 where we unintentionally stopped writing the newest data.
```