Description of problem:
After create pod with sysctls value, then edit 'security.alpha.kubernetes.io/sysctls', the value can be changed but can't take effect, this annotations should be immutable.

Version-Release number of selected component (if applicable):
fork_ami_openshift3_clusterinfra_public_178_299

How reproducible:
Always

Steps to Reproduce:
1.Create a pod with safe sysctls
oc create -f https://raw.githubusercontent.com/mdshuai/testfile-openshift/master/sysctls/pod-sysctl-safe.yaml

2.When the pod is running check the safe value works
[root@dhcp-128-7 dma]# oc get pod 
NAME        READY     STATUS    RESTARTS   AGE
hello-pod   1/1       Running   0          32s
[root@dhcp-128-7 dma]# oc exec hello-pod -- cat /proc/sys/kernel/shm_rmid_forced
1

3.Update 'security.alpha.kubernetes.io/sysctls: kernel.shm_rmid_forced=0'
[root@dhcp-128-7 dma]# oc patch pod hello-pod -p '{"metadata":{"annotations":{"security.alpha.kubernetes.io/sysctls":"kernel.shm_rmid_forced=0"}}}'
"hello-pod" patched
[root@dhcp-128-7 dma]# oc get pod hello-pod -o json|grep shm_rmid_forced
            "security.alpha.kubernetes.io/sysctls": "kernel.shm_rmid_forced=0"

4.Check the sysctls value again in container
[root@dhcp-128-7 dma]# oc exec hello-pod -- cat /proc/sys/kernel/shm_rmid_forced
1

Actual results:
3.Update sysctls value successfully
4.The value is still same with step2.

Expected results:
3.When update should tip sysctls is immutable

Additional info: