Audio: Handle Profile Connection in progress error

Audio: Handle Profile Connection in progress error

Currently, bt-service does not check
if connection request for same device is
already under progress. This allows queuing
up multiple same requests in pending request list.
At the time of replying DBUS context, only one
request is returned & other requests are not freed.
In this patch, BLUETOOTH_ERROR_IN_PROGRESS error
is returned if same profile connection request
is pending.

Change-Id: I1e8ea43d8dc06e73b928c099bab8efc992b4125d
Signed-off-by: Anupam Roy <anupam.r@samsung.com>