Tweak tablet keyboard design

This change introduces,
- center align "More" key label
- remove drop shadow from key label
- darker key label color when manual temporary upper case
- narrower pop up mini keyboard
- remove unnecessary key background from pop up mini keyboard
- smaller key label in portrait

Bug: 3216592
Change-Id: I77e0733f467a88aa32e09fcbace56fe08f755229
diff --git a/java/res/values/styles.xml b/java/res/values/styles.xml
index 6ab4ded..02d21b4 100644
--- a/java/res/values/styles.xml
+++ b/java/res/values/styles.xml
@@ -19,8 +19,10 @@
         <item name="android:background">@drawable/keyboard_background</item>
 
         <item name="keyBackground">@drawable/btn_keyboard_key</item>
-        <item name="keyTextSize">@dimen/key_text_size</item>
+        <item name="keyLetterSize">@dimen/key_letter_size</item>
+        <item name="keyLetterStyle">normal</item>
         <item name="keyTextColor">#FFFFFFFF</item>
+        <item name="keyTextColorDisabled">#FFFFFFFF</item>
         <item name="keyPreviewLayout">@layout/key_preview</item>
         <item name="keyPreviewOffset">@dimen/key_preview_offset</item>
         <item name="keyPreviewHeight">@dimen/key_preview_height</item>