Fix animation for the empty cabinet, also make other animations less jarring.

Setting android:animateLayoutChanges=true was causing flickering and problems
with sliding the cabinet while a fragment transition was already in progress.

Bug: 27060052
Bug: 26952361
Change-Id: I17e5f8b57d63cd9a586fc70ae43e030c4f232e8d
(cherry picked from commit ed82fd7843)

packages/DocumentsUI/res/layout/fragment_directory.xml

@@ -17,8 +17,7 @@
 <com.android.documentsui.DirectoryView xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
-    android:orientation="vertical"
-    android:animateLayoutChanges="true">
+    android:orientation="vertical">
 
     <ProgressBar
         android:id="@+id/progressbar"
@@ -43,6 +42,7 @@
         android:layout_width="match_parent"
         android:layout_height="match_parent"
         android:orientation="vertical"
+        android:background="@color/window_background"
         android:visibility="gone">
 
         <LinearLayout