Simplify logic for connect in MapClientProfile

* connect: remove connected device check logic. MapClientService
  will check it.
* remove member variable V and related checks.
* wrap if/else statement in curly brackets.
* add robotest for MapClientProfile.

Bug: 111812003
Test: make -j42 RunSettingsLibRoboTests ROBOTEST_FILTER=MapClientProfileTest
Change-Id: Ic3620c8910e5acbb14e33369ff437d434b514ddf
(cherry picked from commit a199c59436581b73eaf5dfc4f58f292f7f1fca25)