Check for null executor

Check for null executor when invalid parameters are passed

Test: build
Bug: 135927110
Change-Id: I12014f4da00d3783506642162ad7668fc7c05d9d

telephony/java/android/telephony/TelephonyManager.java

@@ -10884,6 +10884,9 @@ public class TelephonyManager {
         try {
             IOns iOpportunisticNetworkService = getIOns();
             if (iOpportunisticNetworkService == null || availableNetworks == null) {
+                if (executor == null || callback == null) {
+                    return;
+                }
                 Binder.withCleanCallingIdentity(() -> executor.execute(() -> {
                     callback.accept(UPDATE_AVAILABLE_NETWORKS_INVALID_ARGUMENTS);
                 }));