Reduce log severity for transcode fd conversion failure

Converting a transcode fd to the original fd might fail for the more
common reason that the fd is already original.

Now, we log as DEBUG instead of WARNING

Test: m
Bug: 186672282
Change-Id: Ifd0b3cef901ae1c2f467ace06dca590dff8ffb04

core/java/android/os/FileUtils.java

@@ -1470,7 +1470,7 @@ public final class FileUtils {
             return MediaStore.getOriginalMediaFormatFileDescriptor(context,
                     ParcelFileDescriptor.dup(fd));
         } catch (Exception e) {
-            Log.w(TAG, "Failed to convert to modern format file descriptor", e);
+            Log.d(TAG, "Failed to convert to modern format file descriptor", e);
             return null;
         }
     }