[FIX] project: make state and priority field non auto save in page

Before this commit changing priority and state from sub-task
and block-by task saves the unsaved change or even create new
records even though user discard that changes.

This commit add 'auto_save' false to prevent auto save for
sub-task and block-by task page.

task-3282848

closes odoo/odoo#119330

Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>