fix: simple psim with vehicle engage

[takayuki5168]

Related Issue(required)

#300

Description(required)

Reverted features which dropped during .universe porting

• considered /vehicle/engage result for whether simulating or not (simulating only when /vehicle/engage result is true)
• defined default parameter for /vehicle/engage result (current_engage_ variable). Set true by default in launch file.

Review Procedure(required)

Run simple psim and check the reverted functions. (Some other members and I've already verified that this PR worked well)

Related PR(optional)

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[tkimura4]

LGTM