Disable backup of preferences due to the device-specific data contained there

app/src/main/AndroidManifest.xml

@@ -26,6 +26,7 @@
 
     <application
         android:allowBackup="true"
+        android:fullBackupContent="@xml/backup_rules"
         android:isGame="true"
         android:banner="@drawable/atv_banner"
         android:icon="@drawable/ic_launcher"

app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<full-backup-content>
+    <!-- Don't sync preferences because it often contains device-specific data -->
+    <exclude domain="sharedpref" path="."/>
+</full-backup-content>