Mouse hover on a submenu should open it

Currently the entire menu closes if mouse is hovered
over a submenu.

Bug: 35480256
Test: Support7Demos > AppCompat > Popup menu
Change-Id: Icc37ea9d47652dbf9e7176ee56ba0b6712f43c1e
diff --git a/v7/appcompat/src/android/support/v7/view/menu/CascadingMenuPopup.java b/v7/appcompat/src/android/support/v7/view/menu/CascadingMenuPopup.java
index b62127e..d3c2fc8 100644
--- a/v7/appcompat/src/android/support/v7/view/menu/CascadingMenuPopup.java
+++ b/v7/appcompat/src/android/support/v7/view/menu/CascadingMenuPopup.java
@@ -27,6 +27,7 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.annotation.StyleRes;
+import android.support.v4.internal.view.SupportMenu;
 import android.support.v4.view.GravityCompat;
 import android.support.v4.view.ViewCompat;
 import android.support.v7.appcompat.R;
@@ -163,7 +164,7 @@
 
                     // Then open the selected submenu, if there is one.
                     if (item.isEnabled() && item.hasSubMenu()) {
-                        menu.performItemAction(item, 0);
+                        menu.performItemAction(item, SupportMenu.FLAG_KEEP_OPEN_ON_SUBMENU_OPENED);
                     }
                 }
             };