fix: flag not being set in old reviewer

[BrayanDSO]

For some reason, the flag menu items used their code/order as ID before (that may lead to conflicts, so it isn't a good practice).

After 1a96697 they use proper IDs, but those IDs weren't handled at onOptionsItemSelected

Fixes

• Fixes Can’t change "Flag" status from App bar button / menu in Reviewer #17748

How Has This Been Tested?

Issue reproduction steps

Checklist

Please, go through these checks before submitting the PR.

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[lukstbit]

Thanks!

[mikehardy]

nice one