batteryCheck: add new battery threshold for arming (COM_ARM_BAT_MIN)

Signed-off-by: Silvan Fuhrer <silvan@auterion.com>

src/modules/commander/commander_params.c

@@ -1098,3 +1098,20 @@ PARAM_DEFINE_FLOAT(COM_POS_LOW_EPH, -1.0f);
  * @group Commander
  */
 PARAM_DEFINE_INT32(COM_ARMABLE, 1);
+
+/**
+ * Minimum battery level for arming
+ *
+ * Additional battery level check that only allows arming if the state of charge of the emptiest
+ *  connected battery is above this value.
+ *
+ * A value of 0 disables the check.
+ *
+ * @unit norm
+ * @min 0
+ * @max 0.9
+ * @decimal 2
+ * @increment 0.01
+ * @group Commander
+ */
+PARAM_DEFINE_FLOAT(COM_ARM_BAT_MIN, 0.f);