Add API to create Car instance synchronously

A client can create a Car instance with a simple call:
  Car car = Car.createCar(mContext);

car object could be used immedietly to retrieve car managers, no
connection listeners and ugly async code on client side!

Bug: 110324099
Test: m -j;  reworked phantoscope app to use this API and verified it
works

Change-Id: I1d4bcbae859fac8312305e5ed2871e86c43aa2ab
2 files changed