bug fix: TC-127
TC-127 - No notification pop up while incoming call comes on.
It is a phenomenon in which pop-up of OnScreen is not displayed by
notification.Since OnScreen will generate and show Surface if notification
comes, but SystemController does not assume that one application makes two
or more Surfaces.
Repair displayed all the norifications by one surface at OnScreen.
Change-Id: I503a5a9a23eb18ec19b4874afc067ff5e5e314ea
Bug-Tizen: TC-127
Signed-off-by: Ryota Okubi <ryota.okubi@mail.toyota-td.jp>