Fix runtime permissinos toggling and relax XML parsing.

1. Fixed the case where runtime permissons can be toggled by a
   developer via a system property.

2. Relaxed the runtime permission XML parsing to be more fault
   toelrant and consistent wiht the reset of the package manager
   parse code.

3. Fixed a deadlock due to calling in to the activity manager
   with the package manager lock held to kill an app.

Change-Id: I11dfb57ad4d8119baea79227dc2a3fe5e2208515
diff --git a/services/core/java/com/android/server/pm/PackageSetting.java b/services/core/java/com/android/server/pm/PackageSetting.java
index 889164c..a3f4c0b 100644
--- a/services/core/java/com/android/server/pm/PackageSetting.java
+++ b/services/core/java/com/android/server/pm/PackageSetting.java
@@ -70,4 +70,8 @@
     public boolean isForwardLocked() {
         return (pkgPrivateFlags & ApplicationInfo.PRIVATE_FLAG_FORWARD_LOCK) != 0;
     }
+
+    public boolean isSystem() {
+        return (pkgFlags & ApplicationInfo.FLAG_SYSTEM) != 0;
+    }
 }