autotest: Copter sim passes default file instead of setting parms

We're now waiting for the vehicle simulation to provide us a heartbeat
for a non-generic frame before considering it good to fly.

Unfortunately, Copter relies on the parameter file to tell it which
frame to use - and we don't apply parameters from parameter files until
after we've checked the heartbeat.

Passing the file into ArduPilot on the commandline means we don't have
this problem.

Tools/autotest/arducopter.py

@@ -88,6 +88,14 @@ class AutoTestCopter(AutoTest):
     def default_frame(self):
         return "+"
 
+    def apply_defaultfile_parameters(self):
+        # Copter passes in a defaults_filepath in place of applying
+        # parameters afterwards.
+        pass
+
+    def defaults_filepath(self):
+        return self.model_defaults_filepath(self.vehicleinfo_key(), self.frame)
+
     def wait_disarmed_default_wait_time(self):
         return 120