Only allow one movePackage operation in-flight

When a movePackage operation is requested, don't allow multiple requests
to pile up for one package. Once a move is completed, an observer will
receive the message and be allowed to call movePackage again.

Change-Id: Ie3842b6d96446febc0037bf9b8f1ca250735edc2

core/java/android/content/pm/PackageManager.java

@@ -609,6 +609,16 @@ public abstract class PackageManager {
      */
     public static final int MOVE_FAILED_INTERNAL_ERROR = -6;
 
+    /**
+     * Error code that is passed to the {@link IPackageMoveObserver} by
+     * {@link #movePackage(android.net.Uri, IPackageMoveObserver)} if the
+     * specified package already has an operation pending in the
+     * {@link PackageHandler} queue.
+     * 
+     * @hide
+     */
+    public static final int MOVE_FAILED_OPERATION_PENDING = -7;
+
     /**
      * Flag parameter for {@link #movePackage} to indicate that
      * the package should be moved to internal storage if its

core/java/android/content/pm/PackageParser.java

@@ -2791,7 +2791,10 @@ public class PackageParser {
 
         // Additional data supplied by callers.
         public Object mExtras;
-        
+
+        // Whether an operation is currently pending on this package
+        public boolean mOperationPending;
+
         /*
          *  Applications hardware preferences
          */