Move CancelableRunnable to base/

Split off of https://chromium-review.googlesource.com/c/chromium/src/+/6165828,
which will be using CancelableRunnable.

This is common functionality in c++, makes sense to mirror it to java base/

Change-Id: I51dc47e6c42d15d60042d60884c93a60235900e8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6180129
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1408081}