dev_container: fix arg forwarding in entrypoint.sh
dev_container: fix arg forwarding in entrypoint.sh

Without this change, the command

    ./tools/dev_container cargo watch -s "cargo check --workspace"

would end up as

    cargo watch -s cargo check --workspace

inside the docker shell.

Change-Id: I79fed9d23804699032adf359a24d7250c1124b21
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/4021752
Reviewed-by: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>
Commit-Queue: Frederick Mayle <ea3905c3051aaffd2c0d536be61ebbe5b4659ce0@google.com>

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