Pull in headers before checking if the packet is V4 or V6. Adjust pull_len appropriately and refresh header pointers after skb_may_pull

Change-Id: I2e07418720f69c7fa9b34ffe5a4f4753c34a38ed
Merge "Pull in headers before checking if the packet is V4 or V6. Adjust pull_len appropriately and refresh header pointers after skb_may_pull"