Reset Puppeteer state on step_type.first()
Reset Puppeteer state on step_type.first()

Our bots already do this, and this ensures that the puppeteers do too.

Currently all our bots reset their state at the start of each Scenario episode so this isn't a bug (unless people are running puppet bots outside of Scenarios for multiple episodes).

PiperOrigin-RevId: 469998813
Change-Id: Id02b23698eb5a399f67fefc9edfcd536cd176fcc

deepmind/meltingpot,deepmind/meltingpot