Changed logic of stream creation to avoid redundant transition to playing state

Changed logic of stream creation to avoid redundant transition to playing state
(Redundant transition was occurred when stream with
low priority had been added to the active pool with
already playing stream(s) with higher priority)

Change-Id: If25cdd918cf923c1885bb5f8578b61fa80f92af5
Signed-off-by: Ievgen Vagin <i.vagin@samsung.com>