add post_notification permission to manifest

This will allow the package to continue sending notifications on T+

Ignore-AOSP-First: Permission is not yet publicly announced

Bug: 194833441
Test: build, flash, and boot
Change-Id: I24e28b384bd8f7bd9925e8eb67bf66c7b45fc916
diff --git a/Tethering/AndroidManifest.xml b/Tethering/AndroidManifest.xml
index e6444f3..4b2a3ec 100644
--- a/Tethering/AndroidManifest.xml
+++ b/Tethering/AndroidManifest.xml
@@ -39,6 +39,7 @@
     <uses-permission android:name="android.permission.UPDATE_APP_OPS_STATS" />
     <uses-permission android:name="android.permission.UPDATE_DEVICE_STATS" />
     <uses-permission android:name="android.permission.WRITE_SETTINGS" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
 
     <protected-broadcast android:name="com.android.server.connectivity.tethering.DISABLE_TETHERING" />