Unhide ApplicationInfo.volumeUuid.

Apps need it to interact with the new StorageStatsManager APIs.

Test: builds, boots
Bug: 34723750
Change-Id: I274d5bd425cd401e10647959ba18f9956628d810

api/current.txt

@@ -9790,6 +9790,7 @@ package android.content.pm {
     field public int theme;
     field public int uiOptions;
     field public int uid;
+    field public java.lang.String volumeUuid;
   }
 
   public static class ApplicationInfo.DisplayNameComparator implements java.util.Comparator {

api/system-current.txt

@@ -10209,6 +10209,7 @@ package android.content.pm {
     field public int theme;
     field public int uiOptions;
     field public int uid;
+    field public java.lang.String volumeUuid;
   }
 
   public static class ApplicationInfo.DisplayNameComparator implements java.util.Comparator {

api/test-current.txt

@@ -9818,6 +9818,7 @@ package android.content.pm {
     field public int theme;
     field public int uiOptions;
     field public int uid;
+    field public java.lang.String volumeUuid;
   }
 
   public static class ApplicationInfo.DisplayNameComparator implements java.util.Comparator {

core/java/android/app/usage/StorageStatsManager.java

@@ -18,6 +18,7 @@ package android.app.usage;
 
 import android.annotation.WorkerThread;
 import android.content.Context;
+import android.content.pm.ApplicationInfo;
 import android.os.RemoteException;
 import android.os.UserHandle;
 
@@ -99,6 +100,8 @@ public class StorageStatsManager {
      * @param volumeUuid the UUID of the storage volume you're interested in, or
      *            {@code null} to specify the default internal storage.
      * @param uid the UID you're interested in.
+     * @see ApplicationInfo#volumeUuid
+     * @see ApplicationInfo#uid
      */
     @WorkerThread
     public StorageStats queryStatsForUid(String volumeUuid, int uid) {

core/java/android/content/pm/ApplicationInfo.java

@@ -596,8 +596,13 @@ public class ApplicationInfo extends PackageItemInfo implements Parcelable {
      */
     public int largestWidthLimitDp = 0;
 
-    /** {@hide} */
+    /**
+     * UUID of the storage volume on which this application is being hosted. For
+     * apps hosted on the default internal storage at
+     * {@link Environment#getDataDirectory()}, the UUID value is {@code null}.
+     */
     public String volumeUuid;
+
     /** {@hide} */
     public String scanSourceDir;
     /** {@hide} */