Close keyguard user switcher on tap outside

Also closes when tapping the current user.
Also fixes a bug, where the background alpha was
not properly initialized. And while we're at it,
fixes a bug where the user switcher was closable
in simple mode by extending quick settings.

Bug: 17691134
Change-Id: I5444fe42a8a2887ab012ef6cbdcc57ba81a8c1c2
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
index c19bdff..bc2196a 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationPanelView.java
@@ -1012,7 +1012,7 @@
                         ? View.VISIBLE
                         : View.INVISIBLE);
         if (mKeyguardUserSwitcher != null && mQsExpanded && !mStackScrollerOverscrolling) {
-            mKeyguardUserSwitcher.hide(true /* animate */);
+            mKeyguardUserSwitcher.hideIfNotSimple(true /* animate */);
         }
     }