testplans: Add exclude_patterns field to FilePattern.

- A file matches iff it matches pattern and doesn't match any
of exclude_patterns.

- Came up in the context of only running tests for Tast
categories touched by a Tast CL, but will be general behavior
in test planner that can fit other use cases.

BUG=b:175811037
TEST=CQ

Change-Id: I389a95575a083d7cc71f34e0b033c0b8c139aad7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2639938
Reviewed-by: Sean Abraham <seanabraham@chromium.org>
Commit-Queue: Andrew Lamb <andrewlamb@chromium.org>
2 files changed