[Tether13] Move TetheringManager into framework

Move tethering out of ConnectivityService. All client would
use TetheringManager to talk with TetheringService directly.

Bug: 144320246
Test: -build, flash, boot
      -atest TetheringTests

Change-Id: Ib051bea724a256f9c4572b566e46ae7b9c4abe6e
Merged-In: Ib051bea724a256f9c4572b566e46ae7b9c4abe6e
diff --git a/Tethering/AndroidManifest_InProcess.xml b/Tethering/AndroidManifest_InProcess.xml
index 029b6c3..02ea551 100644
--- a/Tethering/AndroidManifest_InProcess.xml
+++ b/Tethering/AndroidManifest_InProcess.xml
@@ -22,11 +22,9 @@
           android:process="system">
     <uses-sdk android:minSdkVersion="29" android:targetSdkVersion="29" />
     <application>
-        <!-- TODO: Using MAINLINE_NETWORK_STACK instead of NETWORK_STACK when tethering run in the
-                   same process with networkstack -->
         <service android:name="com.android.server.connectivity.tethering.TetheringService"
                  android:process="system"
-                 android:permission="android.permission.NETWORK_STACK">
+                 android:permission="android.permission.MAINLINE_NETWORK_STACK">
             <intent-filter>
                 <action android:name="android.net.ITetheringConnector.InProcess"/>
             </intent-filter>