Adds necessary permissions to system apis

adds privileged permission for getCaptivePortalServerUrl
adds tether privileged permission for
startTethering,isTetheringSupported

bug:62348162

Test: make and manual testing
Change-Id: I8eb8e3c9dcd7201abe9ea303ee57fe99073d67eb
diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index f478071..c2786e6 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -1098,6 +1098,7 @@
      * @hide
      */
     @SystemApi
+    @RequiresPermission(android.Manifest.permission.LOCAL_MAC_ADDRESS)
     public String getCaptivePortalServerUrl() {
         try {
             return mService.getCaptivePortalServerUrl();
@@ -2061,10 +2062,11 @@
      * {@hide}
      */
     @SystemApi
-    @RequiresPermission(android.Manifest.permission.ACCESS_NETWORK_STATE)
+    @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED)
     public boolean isTetheringSupported() {
         try {
-            return mService.isTetheringSupported();
+            String pkgName = mContext.getOpPackageName();
+            return mService.isTetheringSupported(pkgName);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
@@ -2094,6 +2096,7 @@
      * @hide
      */
     @SystemApi
+    @RequiresPermission(android.Manifest.permission.TETHER_PRIVILEGED)
     public void startTethering(int type, boolean showProvisioningUi,
             final OnStartTetheringCallback callback) {
         startTethering(type, showProvisioningUi, callback, null);
diff --git a/core/java/android/net/IConnectivityManager.aidl b/core/java/android/net/IConnectivityManager.aidl
index 27729dc..14cee36 100644
--- a/core/java/android/net/IConnectivityManager.aidl
+++ b/core/java/android/net/IConnectivityManager.aidl
@@ -75,7 +75,7 @@
 
     int getLastTetherError(String iface);
 
-    boolean isTetheringSupported();
+    boolean isTetheringSupported(String callerPkg);
 
     void startTethering(int type, in ResultReceiver receiver, boolean showProvisioningUi,
             String callerPkg);
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 224845c..98389a6 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -2973,12 +2973,16 @@
         return mTethering.getTetheredDhcpRanges();
     }
 
+    @Override
+    public boolean isTetheringSupported(String callerPkg) {
+        ConnectivityManager.enforceTetherChangePermission(mContext, callerPkg);
+        return isTetheringSupported();
+    }
+
     // if ro.tether.denied = true we default to no tethering
     // gservices could set the secure setting to 1 though to enable it on a build where it
     // had previously been turned off.
-    @Override
-    public boolean isTetheringSupported() {
-        enforceTetherAccessPermission();
+    private boolean isTetheringSupported() {
         int defaultVal = encodeBool(!mSystemProperties.get("ro.tether.denied").equals("true"));
         boolean tetherSupported = toBool(Settings.Global.getInt(mContext.getContentResolver(),
                 Settings.Global.TETHER_SUPPORTED, defaultVal));
@@ -5380,6 +5384,7 @@
 
     @Override
     public String getCaptivePortalServerUrl() {
+        enforceConnectivityInternalPermission();
         return NetworkMonitor.getCaptivePortalServerHttpUrl(mContext);
     }