Cherry pick task movement changes from aosp

The following cherry picks from aosp contain code that keep windows
tracking the task movement.

https://android-review.googlesource.com/#/c/111380/
https://android-review.googlesource.com/#/c/109930

Maybe fixes bug 15729183.

Change-Id: Ida69fe365b06025d119e32b22a8d04958cdbabf3
diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java
index 9ceac41..a60be3b 100644
--- a/services/core/java/com/android/server/wm/Task.java
+++ b/services/core/java/com/android/server/wm/Task.java
@@ -60,6 +60,12 @@
         return removed;
     }
 
+    void setSendingToBottom(boolean toBottom) {
+        for (int appTokenNdx = 0; appTokenNdx < mAppTokens.size(); appTokenNdx++) {
+            mAppTokens.get(appTokenNdx).sendingToBottom = toBottom;
+        }
+    }
+
     @Override
     public String toString() {
         return "{taskId=" + taskId + " appTokens=" + mAppTokens + "}";
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 837672a..1ba9f27 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -5052,6 +5052,10 @@
                     }
                 }
                 stack.moveTaskToTop(task);
+                if (mAppTransition.isTransitionSet()) {
+                    task.setSendingToBottom(false);
+                }
+                moveStackWindowsLocked(displayContent);
             }
         } finally {
             Binder.restoreCallingIdentity(origId);
@@ -5070,6 +5074,9 @@
                 }
                 final TaskStack stack = task.mStack;
                 stack.moveTaskToBottom(task);
+                if (mAppTransition.isTransitionSet()) {
+                    task.setSendingToBottom(true);
+                }
                 moveStackWindowsLocked(stack.getDisplayContent());
             }
         } finally {