[Adapt] Separate bluetooth service dir

[Adapt] Separate bluetooth service dir

This initial patch does following-

1/Create bluetooth service adaptation
 directory(bt-service-adaptation), which will be used
 for stack adaptation development.

2/Create services folder in bt-service-adaptation. All
 core services (hid, audio, opp, hfp, gatt etc) will be
 created inside the services dir in subsequent patches.

3/Create basic files for bt-service initially inside
 bt-service-adaptation/services dir.

4/Declare environment variable to enable build of
 bt-service-adaptation directory. [If bt_hal is enabled,
 bt-service-adaptation will be built, otherwise bt-service
 will be built]

[Note: Functionalities will be enabled in subsequent patches]

Change-Id: Ib6f8296d30a3f27502c2e0a28e388e043fced1aa
Signed-off-by: Anupam Roy <anupam.r@samsung.com>