Revert "Declare that LatinIME does not use cleartext network traffic."

This reverts commit 24a9683ac9fc1b6d3ac49de449ea4b2f155f26a9.

Change-Id: I6f305aac6ac8d5c550a39eb5c88ec2881203cecc
Reason: Breaks a clean build on master.
diff --git a/java/AndroidManifest.xml b/java/AndroidManifest.xml
index 7e77e77..f58c401 100644
--- a/java/AndroidManifest.xml
+++ b/java/AndroidManifest.xml
@@ -38,8 +38,7 @@
     <application android:label="@string/english_ime_name"
             android:icon="@drawable/ic_launcher_keyboard"
             android:supportsRtl="true"
-            android:allowBackup="true"
-            android:usesCleartextTraffic="false">
+            android:allowBackup="true">
 
         <!-- Services -->
         <service android:name="LatinIME"