/usr/lib/python2.7/dist-packages/trytond/modules/stock_supply_day/view/ is in tryton-modules-stock-supply-day 3.0.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/trytond/modules/stock_supply_day/view/product_supplier_form.xml
/usr/lib/python2.7/dist-packages/trytond/modules/stock_supply_day/view/product_supplier_weekday_form.xml
/usr/lib/python2.7/dist-packages/trytond/modules/stock_supply_day/view/product_supplier_weekday_tree.xml
/usr/lib/python2.7/dist-packages/trytond/modules/stock_supply_day/view/product_supplier_weekday_tree_editable.xml