Add soong config variable for ShannonIms

Bug: 380779042
Test: m ShannonIms
Change-Id: Ifb77cb2dd40410fa9e50740126f7918434b5a275
diff --git a/core/android_soong_config_vars.mk b/core/android_soong_config_vars.mk
index e442f72..8d04c2c 100644
--- a/core/android_soong_config_vars.mk
+++ b/core/android_soong_config_vars.mk
@@ -266,3 +266,4 @@
 # Variables for telephony
 $(call soong_config_set_bool,telephony,sec_cp_secure_boot,$(if $(filter true,$(SEC_CP_SECURE_BOOT)),true,false))
 $(call soong_config_set_bool,telephony,cbd_protocol_sit,$(if $(filter true,$(CBD_PROTOCOL_SIT)),true,false))
+$(call soong_config_set_bool,telephony,use_radioexternal_hal_aidl,$(if $(filter true,$(USE_RADIOEXTERNAL_HAL_AIDL)),true,false))