dev_container: Add --pull option to force trigger docker pull
dev_container: Add --pull option to force trigger docker pull

TEST=./tools/dev_container --pull triggers docker pull
BUG=b:243562713

Change-Id: I4158e433a62f6e7815edaec180b1b294d9ff4d87
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3892524
Auto-Submit: Zihan Chen <610a84a32f2086cdab4679002a95cbb619b0396d@google.com>
Reviewed-by: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>
Commit-Queue: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>

google/crosvm,google/crosvm,google/crosvm,google/crosvm