fix(zigbee): Add getter for RxOnWhenIdle

Author: P-R-O-C-H-Y

Diff for: libraries/Zigbee/src/ZigbeeCore.cpp

@@ -99,7 +99,7 @@ static void esp_zb_task(void *pvParameters) {
 
   //NOTE: This is a workaround to make battery powered devices to be discovered as battery powered
   if (((zigbee_role_t)Zigbee.getRole() == ZIGBEE_END_DEVICE) && edBatteryPowered) {
-    zb_set_ed_node_descriptor(0, _rx_on_when_idle, 1);
+    zb_set_ed_node_descriptor(0, Zigbee.getRxOnWhenIdle(), 1);
   }
 
   esp_zb_stack_main_loop();

Diff for: libraries/Zigbee/src/ZigbeeCore.h

@@ -122,6 +122,9 @@ class ZigbeeCore {
   void setRxOnWhenIdle(bool rx_on_when_idle) {
     _rx_on_when_idle = rx_on_when_idle;
   }
+  bool getRxOnWhenIdle() {
+    return _rx_on_when_idle;
+  }
 
   void setRebootOpenNetwork(uint8_t time);
   void openNetwork(uint8_t time);