Fix blank screen on contact card after extended screen lock

- After viewing the contact card for someone with social
updates and waiting for an extended screen lock (3+ mins),
unlocking the screen brings up a blank contact card.

- Don't set retain instance state = true for ContactLoaderFragment
so that it follows the normal Fragment lifecycle
(and we already take care of saving/restoring state
anyways in that fragment).

- Don't set the contact data to null onLoaderReset() in
COntactLoaderFragment

- Don't show the "updates" header in the updates fragment
if there are no stream items

Bug: 5141991
Change-Id: Icd8693154f756cf423b64524ffcbd850f1c55d9b