Declare that Dialer does not use cleartext network traffic.

This declares to the platform and tools that this app does not use
cleartext network traffic. The platform and tools will be blocking
(on best effort basis) attempts to use such traffic by this app.
For example, attempts to use HTTP (rather than HTTPS) will be blocked.

Bug: 19215516
Change-Id: I33d78928e2b2ff96112a5ba694615ff6c31164a6
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 638c2c4..5b7944d 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -61,7 +61,8 @@
         android:icon="@mipmap/ic_launcher_phone"
         android:hardwareAccelerated="true"
         android:supportsRtl="true"
-        android:backupAgent='com.android.dialer.DialerBackupAgent'>
+        android:backupAgent='com.android.dialer.DialerBackupAgent'
+        android:usesCleartextTraffic="false">
 
         <meta-data android:name="com.google.android.backup.api_key"
             android:value="AEdPqrEAAAAIBXgtCEKQ6W0PXVnW-ZVia2KmlV2AxsTw3GjAeQ" />