Rearrange Pod deletion workflow

[SaranBalaji90]

What type of PR is this?
bug

Which issue does this PR fix:
If regular pods are force deleted when PPSG is used then it will clean up the regular pods.

What does this PR do / Why do we need it:
If we do make this change, then force deleting regular pods will not be supported with PPSG.

If an issue # is not available please add repro steps and logs from IPAMD/CNI showing the issue:
This doesn't change any existing functionality.

Testing done on this change:
Created and deleted regular pods.

Created and deleted branch eni pods -

{"level":"info","ts":"2020-12-08T00:46:39.198Z","caller":"rpc/rpc.pb.go:520","msg":"Received DelNetwork for Sandbox 7e8fa75d4ccb574d391d5e72b6d07c395ed344cd95984135ddfc74e7c9316c89"}
{"level":"debug","ts":"2020-12-08T00:46:39.198Z","caller":"rpc/rpc.pb.go:520","msg":"DelNetworkRequest: ClientVersion:\"varavaj-init-v2-67-g8bd8af2c\" K8S_POD_NAME:\"gw-74464d8645-vz4b9\" K8S_POD_NAMESPACE:\"default\" K8S_POD_INFRA_CONTAINER_ID:\"7e8fa75d4ccb574d391d5e72b6d07c395ed344cd95984135ddfc74e7c9316c89\" Reason:\"PodDeleted\" ContainerID:\"7e8fa75d4ccb574d391d5e72b6d07c395ed344cd95984135ddfc74e7c9316c89\" IfName:\"eth0\" NetworkName:\"aws-cni\" "}
{"level":"debug","ts":"2020-12-08T00:46:39.198Z","caller":"ipamd/rpc_handler.go:198","msg":"UnassignPodIPv4Address: IP address pool stats: total:28, assigned 1, sandbox aws-cni/7e8fa75d4ccb574d391d5e72b6d07c395ed344cd95984135ddfc74e7c9316c89/eth0"}
{"level":"debug","ts":"2020-12-08T00:46:39.198Z","caller":"ipamd/rpc_handler.go:198","msg":"UnassignPodIPv4Address: Failed to find IPAM entry under full key, trying CRI-migrated version"}
{"level":"warn","ts":"2020-12-08T00:46:39.198Z","caller":"ipamd/rpc_handler.go:198","msg":"UnassignPodIPv4Address: Failed to find sandbox _migrated-from-cri/7e8fa75d4ccb574d391d5e72b6d07c395ed344cd95984135ddfc74e7c9316c89/unknown"}

Branch ENI deleted successfully.

Automation added to e2e:
N/A

Will this break upgrades or downgrades. Has updating a running cluster been tested?:
No this doesn't break on upgrades/downgrades

Does this change require updates to the CNI daemonset config files to work?:
No

Does this PR introduce any user-facing change?:
No

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[jayanthvn]

Nice, LGTM :)