Camera: Add linked list for API results

Earlier, as we are using single api result object,
there is a chance that one result overwrites
another and the API thread that's waiting for
lost api result would go into infinate wait.

Change-Id: I5b147d442a9ed82509e379afce1e2549d44e2a9f
CRs-Fixed: 624059
Merge "Camera: Add linked list for API results"