sensor_calibration: refactor and centralize calibration slot logic

- centralize logic for selecting a preferred calibration slot
   - automatically use existing calibration slot if it exists, otherwise
find first available slot, with a preference for a requested index
 - existing commander calibration methods rewrite all calibration slots
to match current sensor ordering

src/modules/commander/Arming/PreFlightCheck/checks/accelerometerCheck.cpp

@@ -69,7 +69,7 @@ bool PreFlightCheck::accelerometerCheck(orb_advert_t *mavlink_log_pub, vehicle_s
 			calibration_valid = true;
 
 		} else {
-			calibration_valid = (calibration::FindCalibrationIndex("ACC", device_id) >= 0);
+			calibration_valid = (calibration::FindCurrentCalibrationIndex("ACC", device_id) >= 0);
 		}
 
 		if (!calibration_valid) {

src/modules/commander/Arming/PreFlightCheck/checks/gyroCheck.cpp

@@ -68,7 +68,7 @@ bool PreFlightCheck::gyroCheck(orb_advert_t *mavlink_log_pub, vehicle_status_s &
 			calibration_valid = true;
 
 		} else {
-			calibration_valid = (calibration::FindCalibrationIndex("GYRO", device_id) >= 0);
+			calibration_valid = (calibration::FindCurrentCalibrationIndex("GYRO", device_id) >= 0);
 		}
 
 		if (!calibration_valid) {

src/modules/commander/Arming/PreFlightCheck/checks/magnetometerCheck.cpp

@@ -70,7 +70,7 @@ bool PreFlightCheck::magnetometerCheck(orb_advert_t *mavlink_log_pub, vehicle_st
 			calibration_valid = true;
 
 		} else {
-			calibration_valid = (calibration::FindCalibrationIndex("MAG", device_id) >= 0);
+			calibration_valid = (calibration::FindCurrentCalibrationIndex("MAG", device_id) >= 0);
 		}
 
 		if (!calibration_valid) {

src/modules/commander/accelerometer_calibration.cpp

@@ -350,9 +350,6 @@ int do_accel_calibration(orb_advert_t *mavlink_log_pub)
 		} else {
 			calibrations[cur_accel].Reset();
 		}
-
-		// reset calibration index to match uORB numbering
-		calibrations[cur_accel].set_calibration_index(cur_accel);
 	}
 
 	if (active_sensors == 0) {
@@ -435,7 +432,7 @@ int do_accel_calibration(orb_advert_t *mavlink_log_pub)
 				calibrations[i].PrintStatus();
 
 
-				if (calibrations[i].ParametersSave()) {
+				if (calibrations[i].ParametersSave(i, true)) {
 					param_save = true;
 					failed = false;
 
@@ -587,9 +584,6 @@ int do_accel_calibration_quick(orb_advert_t *mavlink_log_pub)
 
 			calibration::Accelerometer calibration{arp.device_id};
 
-			// reset cal index to uORB
-			calibration.set_calibration_index(accel_index);
-
 			if (!calibrated || (offset.norm() > CONSTANTS_ONE_G)
 			    || !PX4_ISFINITE(offset(0))
 			    || !PX4_ISFINITE(offset(1))
@@ -601,7 +595,7 @@ int do_accel_calibration_quick(orb_advert_t *mavlink_log_pub)
 				calibration.set_offset(offset);
 				calibration.set_temperature(temperature_avg);
 
-				if (calibration.ParametersSave()) {
+				if (calibration.ParametersSave(accel_index)) {
 					calibration.PrintStatus();
 					param_save = true;
 					failed = false;

src/modules/commander/gyro_calibration.cpp

@@ -202,9 +202,6 @@ int do_gyro_calibration(orb_advert_t *mavlink_log_pub)
 		if (gyro_sub.advertised() && (gyro_sub.get().device_id != 0) && (gyro_sub.get().timestamp > 0)) {
 			worker_data.calibrations[cur_gyro].set_device_id(gyro_sub.get().device_id);
 		}
-
-		// reset calibration index to match uORB numbering
-		worker_data.calibrations[cur_gyro].set_calibration_index(cur_gyro);
 	}
 
 	unsigned try_count = 0;
@@ -274,11 +271,9 @@ int do_gyro_calibration(orb_advert_t *mavlink_log_pub)
 				calibration.set_offset(worker_data.offset[uorb_index]);
 				calibration.set_temperature(worker_data.temperature[uorb_index]);
 
-				calibration.set_calibration_index(uorb_index);
-
 				calibration.PrintStatus();
 
-				if (calibration.ParametersSave()) {
+				if (calibration.ParametersSave(uorb_index, true)) {
 					param_save = true;
 					failed = false;
 

src/modules/commander/mag_calibration.cpp

@@ -914,11 +914,9 @@ calibrate_return mag_calibrate_all(orb_advert_t *mavlink_log_pub, int32_t cal_ma
 
 				current_cal.set_temperature(worker_data.temperature[cur_mag]);
 
-				current_cal.set_calibration_index(cur_mag);
-
 				current_cal.PrintStatus();
 
-				if (current_cal.ParametersSave()) {
+				if (current_cal.ParametersSave(cur_mag, true)) {
 					param_save = true;
 					failed = false;
 
@@ -1018,16 +1016,13 @@ int do_mag_calibration_quick(orb_advert_t *mavlink_log_pub, float heading_radian
 
 				calibration::Magnetometer cal{mag.device_id};
 
-				// force calibration index to uORB index
-				cal.set_calibration_index(cur_mag);
-
 				// use any existing scale and store the offset to the expected earth field
 				const Vector3f offset = Vector3f{mag.x, mag.y, mag.z} - (cal.scale().I() * cal.rotation().transpose() * expected_field);
 				cal.set_offset(offset);
 				cal.set_temperature(mag.temperature);
 
 				// save new calibration
-				if (cal.ParametersSave()) {
+				if (cal.ParametersSave(cur_mag)) {
 					cal.PrintStatus();
 					param_save = true;
 					failed = false;