Merge "Expose PatchWriter for consumption" am: c1c7b9eaa7 am: 5ecdc7df3c am: f7c65e157b am: e6302e4498

Original change: https://android-review.googlesource.com/c/platform/external/bsdiff/+/1768592

Change-Id: I54e6b28de9271f979c7a83aaf539d822653fb2df