DO NOT MERGE - Update prebuild current SDK

    Copied files from lmp-dev branch at #1343976
    http://android-build/builds/git_lmp-dev-linux-sdk_x86_64-sdk/1343976

    Followed the instruction given at :
    go/updateprebuilts
Change-Id: I726bfd534c1a0660c171c8b1abb1b829e52d0d50
diff --git a/current/support/v7/appcompat/res/values-v21/styles_base.xml b/current/support/v7/appcompat/res/values-v21/styles_base.xml
index 4f78a36..bf78ff3 100644
--- a/current/support/v7/appcompat/res/values-v21/styles_base.xml
+++ b/current/support/v7/appcompat/res/values-v21/styles_base.xml
@@ -136,11 +136,17 @@
     <style name="Base.Widget.AppCompat.Light.DropDownItem.Spinner"
            parent="android:Widget.Material.Light.DropDownItem.Spinner"/>
 
-    <style name="Base.Widget.AppCompat.Spinner"
-           parent="android:Widget.Material.Spinner" />
+    <style name="Base.Widget.AppCompat.Spinner" parent="android:Widget.Material.Spinner">
+        <item name="spinnerMode">dropdown</item>
+        <item name="disableChildrenWhenDisabled">true</item>
+        <item name="popupPromptView">@layout/abc_simple_dropdown_hint</item>
+    </style>
 
-    <style name="Base.Widget.AppCompat.Light.Spinner"
-           parent="android:Widget.Material.Light.Spinner"/>
+    <style name="Base.Widget.AppCompat.Light.Spinner" parent="android:Widget.Material.Light.Spinner">
+        <item name="spinnerMode">dropdown</item>
+        <item name="disableChildrenWhenDisabled">true</item>
+        <item name="popupPromptView">@layout/abc_simple_dropdown_hint</item>
+    </style>
 
     <style name="Base.Widget.AppCompat.ListView.Menu"
            parent="android:Widget.ListView.Menu" />