Prepare to replace windows across recreate().

When the activity locally recreates itself, nothing
on the server side is able to prepare preserving windows,
or replacing windows. The activity was trying to defer
removing the old window, but it was just waiting
until the new one was created, not until it was drawn,
thus resulting in a flicker. It's easy to backpack on the
existing replacement infrastructure.

Bug: 28221875
Change-Id: I55fc4ca78e9e11809473fedd8b30b6a6350cf852
diff --git a/bridge/src/com/android/layoutlib/bridge/android/BridgeWindowSession.java b/bridge/src/com/android/layoutlib/bridge/android/BridgeWindowSession.java
index 5a6a00f..7582fda 100644
--- a/bridge/src/com/android/layoutlib/bridge/android/BridgeWindowSession.java
+++ b/bridge/src/com/android/layoutlib/bridge/android/BridgeWindowSession.java
@@ -233,7 +233,7 @@
     }
 
     @Override
-    public void prepareToReplaceChildren(IBinder appToken) {
+    public void prepareToReplaceWindows(IBinder appToken, boolean childrenOnly) {
         // pass for now.
     }