Add keyboard shadow

This CL sets 8dp elevation ot input view in order to cast a shadow
onto underlying application.

Bug: 16210054
Change-Id: I7779c63612fc88e24dde65de3e4e7a45b9d1762f
diff --git a/java/res/values/themes-common.xml b/java/res/values/themes-common.xml
index 110f6b7..f7cb10f 100644
--- a/java/res/values/themes-common.xml
+++ b/java/res/values/themes-common.xml
@@ -20,6 +20,7 @@
 
 <resources xmlns:android="http://schemas.android.com/apk/res/android">
     <style name="KeyboardIcons" />
+    <style name="InputView" />
     <!-- Default theme values -->
     <style name="Keyboard">
         <item name="rowHeight">25%p</item>