Summary:
Instead of relying on system blocks used, we use the file size reported by ls.
Android 11 seems to be more lazy when it comes to fsync'ing so there's a pretty
good chance that if we just check for with `du` or `ls -ls` we will see an "empty" file
because it hasn't been written to disk yet. By the normal `ls` output instead, we'll
just read the file and see how many bytes it's long, which should be more
accurate in all cases.
Changelog: Fix screen recording for Android 11 beta
Reviewed By: jknoxville
Differential Revision: D22283092
fbshipit-source-id: 6d33ca297f1c0734ab4ffc466d9e483aa1a1bdb5
8ff1411f91