Improve use of MAVSDK::Action module

Added more logging.

Type: Improvement
Issue: https://denyspopov.atlassian.net/browse/AZ-19

src/az_drone_controller.cpp

@@ -28,7 +28,7 @@ AzDroneController::AzDroneController(AzMission &mission, QObject *parent)
         this,
         &AzDroneController::missionIndexChangedSlot);
 
-    // Mission controller signal to the slot in this class to finish the flying.
+    // Mission controller signals end of the missions. This will be used to fly to the return point in JSON.
     connect(mMissionController, &AzMissionController::finished, this, &AzDroneController::missionFinishedSlot);
 
     // Healt info update from MAVSDK.
@@ -113,15 +113,17 @@ bool AzDroneController::stateTelemetryModule(void)
 
 bool AzDroneController::stateActionModule(void)
 {
-    // TODO!! Check return value and print warnings and errors.
     mAction = new Action(mSystem);
-    if (mAction == nullptr) {
-        return false;
-    }
 
+    if (mAction != nullptr) {
         mMissionController->setAction(mAction);
         return true;
     }
+    else {
+        qWarning() << "Creating new MAVSDK::Action failed";
+        return false;
+    }
+}
 
 bool AzDroneController::stateReadyForArming(void)
 {