Add GM BSM

Co-Authored-By: garrettpall <76917194+garrettpall@users.noreply.github.com>

selfdrive/car/gm/interface.py

@@ -21,6 +21,7 @@ BUTTONS_DICT = {CruiseButtons.RES_ACCEL: ButtonType.accelCruise, CruiseButtons.D
                 CruiseButtons.MAIN: ButtonType.altButton3, CruiseButtons.CANCEL: ButtonType.cancel}
 
 ACCELERATOR_POS_MSG = 0xbe
+BSM_MSG = 0x142
 
 NON_LINEAR_TORQUE_PARAMS = {
   CAR.BOLT_EUV: [2.6531724862969748, 1.0, 0.1919764879840985, 0.009054123646805178],
@@ -299,6 +300,9 @@ class CarInterface(CarInterfaceBase):
     if ACCELERATOR_POS_MSG not in fingerprint[CanBus.POWERTRAIN]:
       ret.flags |= GMFlags.NO_ACCELERATOR_POS_MSG.value
 
+    # Detect if BSM message is present
+    ret.enableBsm = BSM_MSG in fingerprint[CanBus.POWERTRAIN]
+
     return ret
 
   # returns a car.CarState