Fix minimized dock

- When SysUI crashed, make sure state is up-to-date
- When divider gets invisible, update state because animations
won't finish
- Make sure to keep mMinimizedDock up-to-date in all cases, even
if docked stack is already gone.
- If docked stack is going away, reset minimized state
- Disallow undocking when minimized.

Bug: 27588187
Bug: 27486464
Change-Id: I6ea48562fae3a8df038a690a488580d758681370
diff --git a/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java b/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
index e8cf126..ddd3ea1 100644
--- a/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
+++ b/packages/SystemUI/src/com/android/systemui/stackdivider/Divider.java
@@ -97,6 +97,9 @@
                 if (mVisible != visible) {
                     mVisible = visible;
                     mView.setVisibility(visible ? View.VISIBLE : View.INVISIBLE);
+
+                    // Update state because animations won't finish.
+                    mView.setMinimizedDockStack(mMinimized);
                 }
             }
         });