Fix minimized state messup

We didn't dispatch the change, but still set the field. This lead to
issues where SysUI disagreed on the minimized state. To fix this, we
only check for state changes if the docked stack is visible, but then
dispatch the change always.

Bug: 28445644
Change-Id: Ie460135049c78e11c97f3160994ca4069bf82e6c
diff --git a/services/core/java/com/android/server/wm/DockedStackDividerController.java b/services/core/java/com/android/server/wm/DockedStackDividerController.java
index 381449c..ca68d55 100644
--- a/services/core/java/com/android/server/wm/DockedStackDividerController.java
+++ b/services/core/java/com/android/server/wm/DockedStackDividerController.java
@@ -378,6 +378,9 @@
     }
 
     private void checkMinimizeChanged(boolean animate) {
+        if (mDisplayContent.getDockedStackVisibleForUserLocked() == null) {
+            return;
+        }
         final TaskStack homeStack = mDisplayContent.getHomeStack();
         if (homeStack == null) {
             return;
@@ -412,8 +415,7 @@
     private void setMinimizedDockedStack(boolean minimizedDock, boolean animate) {
         final boolean wasMinimized = mMinimizedDock;
         mMinimizedDock = minimizedDock;
-        if (minimizedDock == wasMinimized
-                || mDisplayContent.getDockedStackVisibleForUserLocked() == null) {
+        if (minimizedDock == wasMinimized) {
             return;
         }