Merge "Expose file utility classes for consumption" am: b4da837b58 am: f6eecf1513 am: d184d39392 am: bc3803f460

Original change: https://android-review.googlesource.com/c/platform/external/bsdiff/+/1917558

Change-Id: I68b9eaf27c09098cc8f601a429684d69f87875dc