Added a persistent feature in WiFi Direct.

Provide a new feature to use persistent group at default.
In the normal connect sequence, if the persistent profile has been
stored, try to use it. Otherwise, a new persistent group is created.
If the persistent profiles are stored over 32, an old profile is
deleted automatically.

Change-Id: Iccb9fa044f1907f0818cd259275e1675f4c3e222
Signed-off-by: Yoshihiko Ikenaga <yoshihiko.ikenaga@jp.sony.com>