tools/dev_container: stop old container if new image is available
tools/dev_container: stop old container if new image is available

When the container image is updated, developers may not notice and
continue running a different version. Detect this and restart the
container.

BUG=b:217465164
TEST=./tools/dev_container while changing image_version

Change-Id: Ib1df871c5c6fba9421c436d39ab7065be966f41e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3469050
Reviewed-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Commit-Queue: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>

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