Automatic merge from submit-queue (batch tested with PRs 35300, 36709, 37643, 37813, 37697)
[etcd] test cleanup: remove unnecessary AddPrefix()
What?
Remove etcdtest.AddPrefix() in tests. They will be automatically prepended in etcd storage.
Why?
ref: #36290#36374
After the change, it will double prepend.
Alter how runtime.SerializeInfo is represented to simplify negotiation
and reduce the need to allocate during negotiation. Simplify the dynamic
client's logic around negotiating type. Add more tests for media type
handling where necessary.
Automatic merge from submit-queue
convert TPR controller to posthook instead of disable flag
Converts the third party resource controller into a posthook using a loopback client instead going direct to etcd. This let's us eliminate more flags and special-casing during initialization. Also, using a client brings us closer to building this without side-effects for downstream composers.
