Set the default temperture based on google documentation recommendation
What does this MR do and why?
Change our default temperature to match with google's guidance.
From the google vertex docs:
For most use cases, try starting with a temperature of 0.2.
The types of tasks we are using it for are logical not creative so lower temperatures should be more suitable, but will produce less variation that feels like natural conversation.
Edited by Allison Browne