Automatic merge from submit-queue
Fix init container update validation for pods
Partial fix#26840
The remaining issues with `kubectl apply` on pods with init containers
are caused by temporary annotation-based representation and
will resolve themselves once init containers leave alpha state.
Also, this PR makes sure internal and external objects don't get mixed up by the
PATCH handler (see related issue #25106).
This PR is an alternative for #28557 which met criticism from @smarterclayton
and @liggitt for working around the temporary issue with annotations.
#28557 is a full fix for #26840 and contains an e2e test that cannot pass
without the `VolumeMounts` workaround. As there appears to be no
good way to include an e2e test that's known to be failing in k8s source,
I've removed it from this PR.
Either this PR or #28557 should be applied, but not both.
165add8692