Reorganize settings in Google Keyboard

Changes :
Input languages ->  Languages
Input preferences -> Preferences
Multi lingual Options -> Multilingual Options
Keyboard Theme -> Theme
Gesture typing preferences -> Gesture typing

**New
 Appearance
        -> Theme
        -> Custom input style

**Removed
 Multilingual options from L dynamically

Bug: 11866784
Change-Id: I07404c27868e1b087b0cafb63d2031a5b493a885
diff --git a/java/res/xml/prefs.xml b/java/res/xml/prefs.xml
index ba285de..c14cd64 100644
--- a/java/res/xml/prefs.xml
+++ b/java/res/xml/prefs.xml
@@ -19,17 +19,17 @@
     xmlns:latin="http://schemas.android.com/apk/res/com.android.inputmethod.latin"
     android:key="english_ime_settings">
     <PreferenceScreen
-        android:fragment="com.android.inputmethod.latin.settings.InputSettingsFragment"
-        android:title="@string/settings_screen_input"
-        android:key="screen_input" />
+        android:fragment="com.android.inputmethod.latin.settings.PreferencesSettingsFragment"
+        android:title="@string/settings_screen_preferences"
+        android:key="screen_preferences" />
     <PreferenceScreen
-        android:fragment="com.android.inputmethod.latin.settings.ThemeSettingsFragment"
-        android:title="@string/keyboard_theme"
-        android:key="screen_theme" />
+        android:fragment="com.android.inputmethod.latin.settings.AppearanceSettingsFragment"
+        android:title="@string/settings_screen_appearance"
+        android:key="screen_appearance" />
     <PreferenceScreen
         android:fragment="com.android.inputmethod.latin.settings.MultiLingualSettingsFragment"
-        android:title="@string/settings_screen_multi_lingual"
-        android:key="screen_multi_lingual" />
+        android:title="@string/settings_screen_multilingual"
+        android:key="screen_multilingual" />
     <PreferenceScreen
         android:fragment="com.android.inputmethod.latin.settings.GestureSettingsFragment"
         android:title="@string/settings_screen_gesture"