accel/gyro/mag calibration set default priority uninitialized

- this allows the default priority to be set differently for internal/external sensors
 - accel and gyro initialize default priority like mag in preparation for fully supporting external sensors
 - fixes #15652

src/lib/sensor_calibration/Accelerometer.hpp

@@ -53,15 +53,15 @@ public:
 	static constexpr const char *SensorString() { return "ACC"; }
 
 	Accelerometer();
-	explicit Accelerometer(uint32_t device_id);
+	explicit Accelerometer(uint32_t device_id, bool external = false);
 
 	~Accelerometer() = default;
 
 	void PrintStatus();
 
 	void set_calibration_index(uint8_t calibration_index) { _calibration_index = calibration_index; }
-	void set_device_id(uint32_t device_id);
-	void set_external(bool external = true) { _external = external; }
+	void set_device_id(uint32_t device_id, bool external = false);
+	void set_external(bool external = true);
 	void set_offset(const matrix::Vector3f &offset) { _offset = offset; }
 	void set_scale(const matrix::Vector3f &scale) { _scale = scale; }
 
@@ -95,7 +95,7 @@ private:
 
 	int8_t _calibration_index{-1};
 	uint32_t _device_id{0};
-	int32_t _priority{DEFAULT_PRIORITY};
+	int32_t _priority{-1};
 
 	bool _external{false};
 };