Use shared app gid for forward-locked processes

Use a shared app gid for each app across different users which allows
forward-locked applications to share the same APK file.

Change-Id: Ifecf51ee7865547117746f83e9733083d3dd5111
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index d5fca4d..05099fb 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -152,10 +152,24 @@
     public static final int LAST_ISOLATED_UID = 99999;
 
     /**
+     * First gid for applications to share resources. Used when forward-locking
+     * is enabled but all UserHandles need to be able to read the resources.
+     * @hide
+     */
+    public static final int FIRST_SHARED_APPLICATION_GID = 50000;
+
+    /**
+     * Last gid for applications to share resources. Used when forward-locking
+     * is enabled but all UserHandles need to be able to read the resources.
+     * @hide
+     */
+    public static final int LAST_SHARED_APPLICATION_GID = 59999;
+
+    /**
      * Defines a secondary group id for access to the bluetooth hardware.
      */
     public static final int BLUETOOTH_GID = 2000;
-    
+
     /**
      * Standard priority of application threads.
      * Use with {@link #setThreadPriority(int)} and