Allow to set boolean params with ros_gz_bridge xml

[ahcorde]

🦟 Bug fix

Summary

I was not able to set

    bridge_params="'qos_overrides./air_pressure.publisher.reliability': 'best_effort', 'use_sim_time': True"/>

because the true internally is a string, this should convert the string in a bool type

Checklist

• Signed all commits for DCO
• Added tests
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
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• All tests passed (See test coverage)
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[ahcorde]

superseed by #663 and #664