Adds showWhenLocked attribute to Activities.

The new attribute allows an Activity such as the alarm to appear
on all users screens.

Bug: 7213805 fixed.
Change-Id: If7866b13d88c04af07debc69e0e875d0adc6050a
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 3ef6767..dcdde76 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -7453,6 +7453,7 @@
         lp.format = v.getBackground().getOpacity();
         lp.flags = WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
                 | WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE;
+        lp.privateFlags |= WindowManager.LayoutParams.PRIVATE_FLAG_SHOW_FOR_ALL_USERS;
         ((WindowManager)mContext.getSystemService(
                 Context.WINDOW_SERVICE)).addView(v, lp);
     }