Shell: Allow usage of wifi usability score APIs

This permission is needed for wifi CTS tests.

Is the minimally scoped permission that needs to be added?
- Yes, this only allows the app to influnce wifi vs lte network
selection algorithm.

What options did you explore that did not need this permission?
- Without this permission, it would be impossible to test these API's:
WifiManager.setWifiConnectedNetworkScorer()
WifiManager.clearWifiConnectedNetworkScorer()
WifiManager.clearWifiConnectedNetworkScorer()
WifiManager.addOnWifiUsabilityStatsListener()

Bug: 150236894
Test: Device boots up.
Change-Id: Ic173e44ab818cdfecebde80715ddaec347019db6
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index 8105114..0230970 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -272,6 +272,9 @@
     <!-- Permission needed to read wifi network credentials for CtsNetTestCases -->
     <uses-permission android:name="android.permission.READ_WIFI_CREDENTIAL" />
 
+    <!-- Permission needed to use wifi usability API's for CtsNetTestCases -->
+    <uses-permission android:name="android.permission.WIFI_UPDATE_USABILITY_STATS_SCORE" />
+
     <!-- Permission needed to test registering pull atom callbacks -->
     <uses-permission android:name="android.permission.REGISTER_STATS_PULL_ATOM" />