[TNU01] Add Tethering notification updater

There are lots of Carrier/OEM requests for tethering
notification customization. So add a new tethering notification
updater class which can let OEM customize the behavior they
wanted.

Bug: 122085773
Test: atest TetheringTests
Change-Id: I7faacde7ac84e93ea0dfe03dd33d2cc41c589225
diff --git a/Tethering/res/values/config.xml b/Tethering/res/values/config.xml
index 379cd18..f825d6b 100644
--- a/Tethering/res/values/config.xml
+++ b/Tethering/res/values/config.xml
@@ -155,4 +155,49 @@
 
     <!-- ComponentName of the service used to run no ui tether provisioning. -->
     <string translatable="false" name="config_wifi_tether_enable">com.android.settings/.wifi.tether.TetherService</string>
+
+    <!-- Enable tethering notification -->
+    <!-- Icons for showing tether enable notification.
+         Each item should have two elements and be separated with ";".
+
+         The first element is downstream types which is one of tethering. This element has to be
+         made by WIFI, USB, BT, and OR'd with the others. Use "|" to combine multiple downstream
+         types and use "," to separate each combinations. Such as
+
+             USB|BT,WIFI|USB|BT
+
+         The second element is icon for the item. This element has to be composed by
+         <package name>:drawable/<resource name>. Such as
+
+             1. com.android.networkstack.tethering:drawable/stat_sys_tether_general
+             2. android:drawable/xxx
+
+         So the entire string of each item would be
+
+             USB|BT,WIFI|USB|BT;com.android.networkstack.tethering:drawable/stat_sys_tether_general
+
+         NOTE: One config can be separated into two or more for readability. Such as
+
+               WIFI|USB,WIFI|BT,USB|BT,WIFI|USB|BT;android:drawable/xxx
+
+               can be separated into
+
+               WIFI|USB;android:drawable/xxx
+               WIFI|BT;android:drawable/xxx
+               USB|BT;android:drawable/xxx
+               WIFI|USB|BT;android:drawable/xxx
+
+         Notification will not show if the downstream type isn't listed in array.
+         Empty array means disable notifications. -->
+    <!-- In AOSP, hotspot is configured to no notification by default. Because status bar has showed
+         an icon on the right side already -->
+    <string-array translatable="false" name="tethering_notification_icons">
+        <item>USB;com.android.networkstack.tethering:drawable/stat_sys_tether_usb</item>
+        <item>BT;com.android.networkstack.tethering:drawable/stat_sys_tether_bluetooth</item>
+        <item>WIFI|USB,WIFI|BT,USB|BT,WIFI|USB|BT;com.android.networkstack.tethering:drawable/stat_sys_tether_general</item>
+    </string-array>
+    <!-- String for tether enable notification title. -->
+    <string name="tethering_notification_title">@string/tethered_notification_title</string>
+    <!-- String for tether enable notification message. -->
+    <string name="tethering_notification_message">@string/tethered_notification_message</string>
 </resources>