Add support for "Audiobooks".

Bug: 113356944
Test: manual
Change-Id: Ifed54c41a533ed2d556dc6561ea498ec293991a6
diff --git a/core/java/android/os/Environment.java b/core/java/android/os/Environment.java
index 0c1aae8..8904ee6 100644
--- a/core/java/android/os/Environment.java
+++ b/core/java/android/os/Environment.java
@@ -657,6 +657,12 @@
     public static String DIRECTORY_SCREENSHOTS = "Screenshots";
 
     /**
+     * Standard directory in which to place any audio files which are
+     * audiobooks.
+     */
+    public static String DIRECTORY_AUDIOBOOKS = "Audiobooks";
+
+    /**
      * List of standard storage directories.
      * <p>
      * Each of its values have its own constant:
@@ -671,6 +677,7 @@
      *   <li>{@link #DIRECTORY_DOWNLOADS}
      *   <li>{@link #DIRECTORY_DCIM}
      *   <li>{@link #DIRECTORY_DOCUMENTS}
+     *   <li>{@link #DIRECTORY_AUDIOBOOKS}
      * </ul>
      * @hide
      */
@@ -684,7 +691,8 @@
             DIRECTORY_MOVIES,
             DIRECTORY_DOWNLOADS,
             DIRECTORY_DCIM,
-            DIRECTORY_DOCUMENTS
+            DIRECTORY_DOCUMENTS,
+            DIRECTORY_AUDIOBOOKS,
     };
 
     /**
@@ -709,6 +717,7 @@
     /** {@hide} */ public static final int HAS_DOWNLOADS = 1 << 7;
     /** {@hide} */ public static final int HAS_DCIM = 1 << 8;
     /** {@hide} */ public static final int HAS_DOCUMENTS = 1 << 9;
+    /** {@hide} */ public static final int HAS_AUDIOBOOKS = 1 << 10;
 
     /** {@hide} */ public static final int HAS_ANDROID = 1 << 16;
     /** {@hide} */ public static final int HAS_OTHER = 1 << 17;
@@ -738,6 +747,7 @@
                 else if (DIRECTORY_DOWNLOADS.equals(name)) res |= HAS_DOWNLOADS;
                 else if (DIRECTORY_DCIM.equals(name)) res |= HAS_DCIM;
                 else if (DIRECTORY_DOCUMENTS.equals(name)) res |= HAS_DOCUMENTS;
+                else if (DIRECTORY_AUDIOBOOKS.equals(name)) res |= HAS_AUDIOBOOKS;
                 else if (DIRECTORY_ANDROID.equals(name)) res |= HAS_ANDROID;
                 else res |= HAS_OTHER;
             }