Relax global restrict for system services.

Since we control system services, we can ensure they are using little
data when data usage is globally restricted.  Continue restricting
AID_MEDIA and AID_DRM, since they respond to app requests.

Bug: 6377903, 5772564
Change-Id: I196bf334f903397ea6a67e6802240ee792e47b54
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index 770bf1c..8eb1928 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -92,6 +92,12 @@
     public static final int MEDIA_UID = 1013;
 
     /**
+     * Defines the UID/GID for the DRM process.
+     * @hide
+     */
+    public static final int DRM_UID = 1019;
+
+    /**
      * Defines the GID for the group that allows write access to the SD card.
      * @hide
      */