Place InputMethod after DockedDivider in window list.

We need to ensure that the InputMethod ends up
after the docked divider so it will have a higher
Z-order for input.

Bug: 28184654
Change-Id: Ifbe943312a82a79e850f106cc906f3749737710d

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

@@ -663,4 +663,8 @@ public class DockedStackDividerController implements DimLayerUser {
     public String toShortString() {
         return TAG;
     }
-}
+
+    WindowState getWindow() {
+        return mWindow;
+    }
+}

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

@@ -1563,6 +1563,16 @@ public class WindowManagerService extends IWindowManager.Stub
                     mLayersController.setInputMethodAnimLayerAdjustment(0);
                 }
             }
+
+            // If the docked divider is visible, we still need to go through this whole
+            // excercise to find the appropriate input method target (used for animations
+            // and dialog adjustments), but for purposes of Z ordering we simply wish to
+            // place it above the docked divider.
+            WindowState dockedDivider = w.mDisplayContent.mDividerControllerLocked.getWindow();
+            if (dockedDivider != null && dockedDivider.isVisibleLw()) {
+                int dividerIndex = windows.indexOf(dockedDivider);
+                return dividerIndex > 0 ? dividerIndex + 1 : i + 1;
+            }
             return i+1;
         }
         if (willMove) {