revert(autoware_launch): "feat(autoware_launch): use mrm handler by default (#1043)"

This reverts commit d076aa5f93f4016bcd772a22094f44d93deeecaa.

Description

My understanding is that previously there was a process to ignore the emergency state before route setting. However, by switching to the diagnostics graph, a problem arose where the state becomes emergency when scenario_simulator_v2 starts up, causing the simulation to fail. I propose temporarily pending the switch to the diagnostics graph until this issue is fixed.

Tests performed

[x] PASS TIERIV INTERNAL SCENARIOS
[x] run sceanrio_simulator_v2 in local environment

Effects on system behavior

Not applicable.

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autowarefoundation / autoware_launch