Update DownloadStorageProvider to include MediaStore.Downloads.

Bug: 120879205
Test: manual
Test: atest DownloadProviderTests
Test: atest cts/tests/app/src/android/app/cts/DownloadManagerTest.java
Test: atest MediaProviderTests
Test: atest cts/tests/tests/provider/src/android/provider/cts/MediaStore*
Change-Id: I44be836899437d87fc1a00e5fe316c6b68488643
diff --git a/core/java/android/app/DownloadManager.java b/core/java/android/app/DownloadManager.java
index 853b45e..acc7094 100644
--- a/core/java/android/app/DownloadManager.java
+++ b/core/java/android/app/DownloadManager.java
@@ -1067,7 +1067,12 @@
      * COLUMN_* constants.
      */
     public Cursor query(Query query) {
-        Cursor underlyingCursor = query.runQuery(mResolver, UNDERLYING_COLUMNS, mBaseUri);
+        return query(query, UNDERLYING_COLUMNS);
+    }
+
+    /** @hide */
+    public Cursor query(Query query, String[] projection) {
+        Cursor underlyingCursor = query.runQuery(mResolver, projection, mBaseUri);
         if (underlyingCursor == null) {
             return null;
         }