Fix captive portal app can be launched w/o MAINLINE_NETWORK_STACK permission

Caller should get SecurityException if called
ConnectivityManager#startCaptivePortalApp() w/o
MAINLINE_NETWORK_STACK permission. But now it will not get any
exception and can launch captive portal app successfully.

Bug: 132662433
Test: atest android.net.cts.ConnectivityManagerTest#testStartCaptivePortalApp
      w and w/o MAINLINE_NETWORK_STACK permission
Test: atest FrameworksNetTests NetworkStackTests

Change-Id: I61be1b0647f4165665a2d4166311adeac956e0d4
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 562199a..b3b5e45 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -3495,7 +3495,8 @@
      */
     @Override
     public void startCaptivePortalAppInternal(Network network, Bundle appExtras) {
-        mContext.checkCallingOrSelfPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK);
+        mContext.enforceCallingOrSelfPermission(NetworkStack.PERMISSION_MAINLINE_NETWORK_STACK,
+                "ConnectivityService");
 
         final Intent appIntent = new Intent(ConnectivityManager.ACTION_CAPTIVE_PORTAL_SIGN_IN);
         appIntent.putExtras(appExtras);