Fix department selector on submit image page

[sea-kelp]

Description of Changes

Fix bug where submit image page department selector was not submitting images to the correct department.

It looks like the current implementation was using selectedIndex (the index of the selected <option> element in the <select>) as the initial department id, which assumes the departments are loaded in order:

OpenOversight/OpenOversight/app/templates/submit_image.html

Lines 79 to 82 in 2c5ad9a

	// Select user's preferred department by default
	document.getElementById("department").selectedIndex = {{ preferred_dept_id }} - 1;
	// Save the preferred department in dept_id
	let dept_id = document.getElementById("department").selectedIndex + 1;

Notes for Deployment

None!

Screenshots (if appropriate)

N/A

Testing instructions

1. Log in as admin user.
2. Create a new department "Bellevue Police Department (BPD)" at http://localhost:3000/departments/new.
3. Update the preferred department to BPD at http://localhost:3000/auth/change-dept/.
4. Go to the Submit Image page (http://localhost:3000/submit) and confirm that the populated department is BPD.
5. Upload an image.
6. Verify in devtools that an image was submitted to http://localhost:3000/upload/departments/2.
7. Update the department selector to SPD.
8. Upload an image.
9. Verify in devtools that an image was submitted to http://localhost:3000/upload/departments/1.
10. Change the preferred department to SPD at http://localhost:3000/auth/change-dept/.
11. Go to the Submit Image page (http://localhost:3000/submit) and confirm that the populated department is now SPD.
12. Upload an image.
13. Verify in devtools that an image was submitted to http://localhost:3000/upload/departments/1.

Checks

• I have rebased my changes on main

• just lint passes

• just test passes