Use visiblePath instead of path for findDocumentPath

Test: atest DocumentsUIGoogleTests
Bug: 158142289

Change-Id: Id46ac014ad87af052b684e21b9242f762d7db80a
diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
index 8f919c3..132922a 100644
--- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
+++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java
@@ -520,9 +520,11 @@
         final RootInfo root = resolvedDocId.first;
         File child = resolvedDocId.second;
 
+        final File rootFile = root.visiblePath != null ? root.visiblePath
+                : root.path;
         final File parent = TextUtils.isEmpty(parentDocId)
-                        ? root.path
-                        : getFileForDocId(parentDocId);
+                ? rootFile
+                : getFileForDocId(parentDocId);
 
         return new Path(parentDocId == null ? root.rootId : null, findDocumentPath(parent, child));
     }