Fixed to prevent usagestats file corruption when writing

Currently, usagestats file may be currupted when writing
fails. Because AtomicFile#failWrite(fos) is always called
with argument null. Modify argument of this method so that
it is not null when writing fails.

Bug: 177501256
Change-Id: I1bb64a9af7941ab80abe3f98ad5b8ecf6d1b46d6
1 file changed