Initial import of bencher v0.1.5 am: d036b627b0 am: 0d26d433f1

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/bencher/+/1533314

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I000df6cf575dde0ce01304288a36960972ca4915