Telephony provider does not use cleartext network traffic.

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

Bug: 19215516
Change-Id: I92d33046f6b2a6fb9a246f56d76edc9cbfb70d7d
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 43e5e69..4cb77be 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -27,7 +27,8 @@
                  android:allowClearUserData="false"
                  android:allowBackup="false"
                  android:label="@string/app_label"
-                 android:icon="@mipmap/ic_launcher_phone">
+                 android:icon="@mipmap/ic_launcher_phone"
+                 android:usesCleartextTraffic="false">
 
         <provider android:name="TelephonyProvider"
                   android:authorities="telephony"