stream-manager: Add conditions not to notify stream connection/disconnection twice

stream-manager: Add conditions not to notify stream connection/disconnection twice

This notification invokes HAL function for stream connection changed.
There were cases that this functions is invoked twice unintentionally
according to the scenario related to calling cork/uncork from client
side. For example, gstreamer pulsesink and playbacks from sound-server.

It is now fixed to trigger the notification one at a time properly.

[Version] 13.0.8
[Issue Type] Improvement

Change-Id: I1ef748ad514c87e01034e4f5bd8fc9b1083be34b
Signed-off-by: Sangchul Lee <sc11.lee@samsung.com>