Automatic merge from submit-queue

Quota ignores pod compute resources on updates

Scenario:

1. define a quota Q that tracks memory and cpu
2. create pod P that uses memory=100Mi, cpu=100m
3. update pod P to use memory=50Mi,cpu=10m

Expected Results:
Step 3 should fail with validation error.
Quota Q should not have changed.

Actual Results:
Step 3 fails validation, but quota Q is decremented to have memory usage down 50Mi and cpu usage down 40m.  This is because the quota was getting updated even though the pod was going to fail validation.

Fix:
Quota should only support modifying pod compute resources when pods themselves support modifying their compute resources.

This also fixes https://github.com/kubernetes/kubernetes/issues/24352

/cc @smarterclayton - this is what we discussed.

fyi: @kubernetes/rh-cluster-infra