rotation: WORKAROUND for avoiding wrong rotation complete UI.

rotation: WORKAROUND for avoiding wrong rotation complete UI.

Until now, we have assumed that the buffer commit event after the rotation
ack event informs us of completion of rotation. However this assumption could
be wrong because the rotation ack event is dispatched by main thread of client,
whereas the buffer commit event could be dispatched by other thread.

The ideal solution for resolving this issue is introduction of same protocol
serial number between the rotation ack event and buffer commit event. But this
approach needs much of changes for EFL, E20 and DDK. Thus I have added workaround
code for quick resolving this.

We have to extend EFL, E20 and DDK to support this later.

Change-Id: I0630ce5d2e801d0fd995141e4c20f43df9aa362e