Add advanced settings screen

Also add an option for popup dismissal delay so as to inaugurate the
new screen.  Besides, remove a path for options to escape from
LatinIME and replace with a direct read from the settings.

Change-Id: I7ec6e724262871fa6523506ecc39f65c5fbe34da
diff --git a/java/res/xml/prefs.xml b/java/res/xml/prefs.xml
index 24a1d45..b0497a5 100644
--- a/java/res/xml/prefs.xml
+++ b/java/res/xml/prefs.xml
@@ -130,6 +130,15 @@
           android:entries="@array/keyboard_layout_modes"
           android:defaultValue="@string/config_default_keyboard_theme_id" />
     </PreferenceCategory>
+    <PreferenceScreen
+          android:key="pref_advanced_settings"
+          android:title="@string/advanced_settings"
+          android:summary="@string/advanced_settings_summary">
+          <!-- Values for popup dismiss delay are added programatically -->
+          <ListPreference
+              android:key="pref_key_preview_popup_dismiss_delay"
+              android:title="@string/key_preview_popup_dismiss_delay" />
+    </PreferenceScreen>
     <!-- <Preference
         android:title="Debug Settings"
         android:key="debug_settings">