Use collapseDefault to indicate what the collapse status of a grid is when viewed for the first time by a user.

Class	grid
Property	gd.collapseDefault
Formal specification	gd.collapseDefault = collapsed \| expanded \| disabled
Required	no
Default	expanded
Version	1.11
Comment	The grid will be showed according to the user selected status, when the user toggles the collapse status. For instance if the collapse default is 'collapsed' and the user expands the grid, the next time the user views an issue containing the same custom field, the grid will be showed expanded. When the gd.ccollapseDefault is set to disabled users will not be able to collapse grids When editing a grid, it will be expanded by default.
Example	`gd.collapseDefault = collapsed`
Reference

Table Grid Editor (legacy) Documentation

gd.collapseDefault