Add config_default_keyboard_theme_id resource

Change-Id: Ie4e9e85694cfd43fcd1fdfeeaa477f13c372a8a6
diff --git a/java/res/values-xlarge/config.xml b/java/res/values-xlarge/config.xml
index 4ceca45..e8e2130 100644
--- a/java/res/values-xlarge/config.xml
+++ b/java/res/values-xlarge/config.xml
@@ -27,6 +27,8 @@
     <bool name="config_sliding_key_input_enabled">false</bool>
     <!-- Whether or not Popup on key press is enabled by default -->
     <bool name="config_default_popup_preview">false</bool>
+    <!-- This configuration is the index of the array {@link KeyboardSwitcher.KEYBOARD_THEMES}. -->
+    <string name="config_default_keyboard_theme_id">5</string>
     <string name="config_text_size_of_language_on_spacebar">medium</string>
     <integer name="config_max_popup_keyboard_column">9</integer>
 </resources>
diff --git a/java/res/values/config.xml b/java/res/values/config.xml
index 5db2e82..8bdda55 100644
--- a/java/res/values/config.xml
+++ b/java/res/values/config.xml
@@ -44,6 +44,8 @@
     <integer name="config_long_press_shift_key_timeout">1200</integer>
     <integer name="config_touch_noise_threshold_millis">40</integer>
     <dimen name="config_touch_noise_threshold_distance">2.0mm</dimen>
+    <!-- This configuration is the index of the array {@link KeyboardSwitcher.KEYBOARD_THEMES}. -->
+    <string name="config_default_keyboard_theme_id">4</string>
     <string name="config_text_size_of_language_on_spacebar">small</string>
     <integer name="config_max_popup_keyboard_column">9</integer>
     <!-- Whether or not auto-correction should be enabled by default -->
diff --git a/java/res/xml/prefs_for_debug.xml b/java/res/xml/prefs_for_debug.xml
index c42fe66..2dad171 100644
--- a/java/res/xml/prefs_for_debug.xml
+++ b/java/res/xml/prefs_for_debug.xml
@@ -32,7 +32,7 @@
             android:persistent="true"
             android:entryValues="@array/keyboard_layout_modes_values"
             android:entries="@array/keyboard_layout_modes"
-            android:defaultValue="5"
+            android:defaultValue="@string/config_default_keyboard_theme_id"
             />
 
     <CheckBoxPreference