fix(bt): fixed -Write-strings warning in btm_ble_5_gap.c

components/bt/host/bluedroid/stack/btm/btm_ble_5_gap.c

@@ -35,7 +35,7 @@ typedef struct {
 tBTM_EXT_ADV_RECORD adv_record[MAX_BLE_ADV_INSTANCE] = {0};
 extern void btm_ble_inter_set(bool extble_inter);
 
-static char *btm_ble_hci_status_to_str(tHCI_STATUS status)
+static const char *btm_ble_hci_status_to_str(tHCI_STATUS status)
 {
     switch(status) {
     case HCI_SUCCESS: