Add Dockerfile/script to build fiddler backend

See also http://go/louhicl/159520 and http://review.skia.org/896598

This draws heavy inspiration from https://github.com/google/skia/blob/main/docker/skia-release/Dockerfile

Change-Id: Ie04558f3dccc17429badf965f8c8859deff8a77d
Bug: b/361559681
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/895196
Auto-Submit: Kaylee Lubick <kjlubick@google.com>
Commit-Queue: Kaylee Lubick <kjlubick@google.com>
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
2 files changed