Problem description: According to user documentation fields "Update interval" and "Timeout" must support LLD macros.
Unfortunately, both of these fields do not support LLD macros:

Steps to reproduce:

1. Open the list of LLD rules for any host
2. Create an LLD rule
3. Open the list of item prototypes for this LLD rule
4. Press "Create item prototype" button
5. In the opened form fill in all mandatory fields
6. Fill in an LLD macro in "Update interval" and "Timeout" fields.
7. Attempt to save the form.

Result: Form is not saved, errors like in the screenshot above are observed.
Expected: According to user documentation "Update interval" and "Timeout" fields should support usage of LLD macros.