Telecomm: Don't re-create CallActivity when rotating screen

MO a call when the device is landscape mode, the ActivityManager will
start CallActivity twice around receiving an orientation change event.
The first time, it is started in the portrait mode, and then it will be
started in the landscape mode after orientation changed event occurred.
As a result, there will be two call object with PRE_DIAL_WAIT state,
and after pressing back key, one call will be disconnected, another
will still exist in CallList, so InCallPresenter can not switch to NO_CALLS.

Don't re-create CallActivity when rotating screen.

CRs-Fixed: 762454

Change-Id: I8c10f2c24cb4e9ca082ded20590b49151c3a7e8b