Add null check before trying to give appOps to package.

Test: none
Bug: 164209140
Change-Id: I64184e9d035be538684c42c85c869f09b048069f

telephony/common/com/android/internal/telephony/SmsApplication.java

@@ -760,6 +760,7 @@ public final class SmsApplication {
     private static void assignExclusiveSmsPermissionsToSystemApp(Context context,
             PackageManager packageManager, AppOpsManager appOps, String packageName,
             boolean sigatureMatch) {
+        if (packageName == null) return;
         // First check package signature matches the caller's package signature.
         // Since this class is only used internally by the system, this check makes sure
         // the package signature matches system signature.