Adding initial app framework

Change-Id: I0c53e3487eb3be1eefa2d0c7f260a90d82fd8844
diff --git a/app/src/main/res/xml/pref_headers.xml b/app/src/main/res/xml/pref_headers.xml
new file mode 100644
index 0000000..f2af3f2
--- /dev/null
+++ b/app/src/main/res/xml/pref_headers.xml
@@ -0,0 +1,17 @@
+<preference-headers xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <!-- These settings headers are only used on tablets. -->
+
+    <header
+        android:fragment="nfd.named_data.net.nfd.NfdSettingsActivity$GeneralPreferenceFragment"
+        android:title="@string/pref_header_general"/>
+
+    <header
+        android:fragment="nfd.named_data.net.nfd.NfdSettingsActivity$NotificationPreferenceFragment"
+        android:title="@string/pref_header_notifications"/>
+
+    <header
+        android:fragment="nfd.named_data.net.nfd.NfdSettingsActivity$DataSyncPreferenceFragment"
+        android:title="@string/pref_header_data_sync"/>
+
+</preference-headers>