fix infinite loop in enableModem TC

Bug: 227585563
Test: run vts -m VtsHalRadioTargetTest
Change-Id: I879faa5ecef026865d17ad1a23e52cb9f8f70454
diff --git a/radio/aidl/vts/radio_modem_response.cpp b/radio/aidl/vts/radio_modem_response.cpp
index d2715a8..20b44c5 100644
--- a/radio/aidl/vts/radio_modem_response.cpp
+++ b/radio/aidl/vts/radio_modem_response.cpp
@@ -24,6 +24,7 @@
 
 ndk::ScopedAStatus RadioModemResponse::enableModemResponse(const RadioResponseInfo& info) {
     rspInfo = info;
+    enableModemResponseToggle = !enableModemResponseToggle;
     parent_modem.notify(info.serial);
     return ndk::ScopedAStatus::ok();
 }