EKF: Add required flags to parameters

This marks the learned bias parameters as volatile (as they change in flight without external configuration) and marks them as system level, which should hide them by default from the UI

src/modules/ekf2/ekf2_params.c

@@ -978,6 +978,8 @@ PARAM_DEFINE_FLOAT(EKF2_RNG_PITCH, 0.0f);
  * @min -0.5
  * @max 0.5
  * @reboot_required true
+ * @volatile
+ * @level system
  * @unit mGauss
  * @decimal 3
  */
@@ -991,6 +993,8 @@ PARAM_DEFINE_FLOAT(EKF2_MAGBIAS_X, 0.0f);
  * @min -0.5
  * @max 0.5
  * @reboot_required true
+ * @volatile
+ * @level system
  * @unit mGauss
  * @decimal 3
  */
@@ -1004,6 +1008,8 @@ PARAM_DEFINE_FLOAT(EKF2_MAGBIAS_Y, 0.0f);
  * @min -0.5
  * @max 0.5
  * @reboot_required true
+ * @volatile
+ * @level system
  * @unit mGauss
  * @decimal 3
  */
@@ -1014,6 +1020,7 @@ PARAM_DEFINE_FLOAT(EKF2_MAGBIAS_Z, 0.0f);
  *
  * @group EKF2
  * @reboot_required true
+ * @level system
  */
 PARAM_DEFINE_INT32(EKF2_MAGBIAS_ID, 0);