Improve settings around MAX_PAGEPILE_SIZE
- Increase max page pile size to 230. I tested the production build with this upper limit and noticed no issues. I think we can safely test it on Toolforge.
- Fix a bug that prevented MAX_PAGEPILE_SIZE from being set via envvar. With this fix, we'll be able to modify MAX_PAGEPILE_SIZE in the Toolforge deployment without redeploying the application.
Bug: T378644