no-op: Remove checkAndNotifyCommonError with ResultReceiver

There are currently two variants of checkAndNotifyCommonError that do
the exactly the same thing, except one uses IIntResultListener and
another uses ResultReceiver. Remove the lesser-used ResultReceiver
variant and just use the IIntResultListener instead (with a
IIntResultListener wrapper for the ResultReceiver).

Bug: 216524590
Test: covered by existing tests
Change-Id: I292a96b32cd975852a52c7953b03bcb35728db24
diff --git a/Tethering/src/com/android/networkstack/tethering/TetheringService.java b/Tethering/src/com/android/networkstack/tethering/TetheringService.java
index b553f46..f501a50 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetheringService.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetheringService.java
@@ -173,7 +173,21 @@
         @Override
         public void requestLatestTetheringEntitlementResult(int type, ResultReceiver receiver,
                 boolean showEntitlementUi, String callerPkg, String callingAttributionTag) {
-            if (checkAndNotifyCommonError(callerPkg, callingAttributionTag, receiver)) return;
+            // Wrap the app-provided ResultReceiver in an IIntResultListener in order to call
+            // checkAndNotifyCommonError with it.
+            IIntResultListener listener = new IIntResultListener() {
+                @Override
+                public void onResult(int i) {
+                    receiver.send(i, null);
+                }
+
+                @Override
+                public IBinder asBinder() {
+                    throw new UnsupportedOperationException("asBinder unexpectedly called on"
+                            + " internal-only listener");
+                }
+            };
+            if (checkAndNotifyCommonError(callerPkg, callingAttributionTag, listener)) return;
 
             mTethering.requestLatestTetheringEntitlementResult(type, receiver, showEntitlementUi);
         }
@@ -277,27 +291,6 @@
             return false;
         }
 
-        private boolean checkAndNotifyCommonError(final String callerPkg,
-                final String callingAttributionTag, final ResultReceiver receiver) {
-            if (!checkPackageNameMatchesUid(getBinderCallingUid(), callerPkg)) {
-                Log.e(TAG, "Package name " + callerPkg + " does not match UID "
-                        + getBinderCallingUid());
-                receiver.send(TETHER_ERROR_NO_CHANGE_TETHERING_PERMISSION, null);
-                return true;
-            }
-            if (!hasTetherChangePermission(callerPkg, callingAttributionTag,
-                    false /* onlyAllowPrivileged */)) {
-                receiver.send(TETHER_ERROR_NO_CHANGE_TETHERING_PERMISSION, null);
-                return true;
-            }
-            if (!mTethering.isTetheringSupported() || !mTethering.isTetheringAllowed()) {
-                receiver.send(TETHER_ERROR_UNSUPPORTED, null);
-                return true;
-            }
-
-            return false;
-        }
-
         private boolean hasNetworkSettingsPermission() {
             return checkCallingOrSelfPermission(NETWORK_SETTINGS);
         }