Fix test failure due to hanging layout

Moved postdrawtransaction application to layout pass, but didn't
set layoutNeeded.

Bug: 200134598
Test: atest MagnifierTest
Change-Id: Ic1be2db52469645d4da12c449c3e13cdb746e7ee

services/core/java/com/android/server/wm/WindowStateAnimator.java

@@ -250,10 +250,10 @@ class WindowStateAnimator {
             // away.
             if (mLastHidden && mDrawState != NO_SURFACE && !forceApplyNow) {
                 mPostDrawTransaction.merge(postDrawTransaction);
-                layoutNeeded = true;
             } else {
                 mWin.getSyncTransaction().merge(postDrawTransaction);
             }
+            layoutNeeded = true;
         }
 
         return layoutNeeded;