Explain that system services may rely on location services

### Problem

Some system services like automatic timezone rely on location services and turning it off completely will break those features without warning

### Proposal

Add some explanation to the description text here that clarifies that disabling this means disabling the location portal dialog completely as well as shutting off location access from system services. Apps still have to ask for permission even when this switch is on

### Prior Art (Optional)

_No response_

Start by locating the description text for the location-services switch in this repository. Update it to explain that disabling the switch also disables the location portal dialog and location access for system services, while apps must still request permission. Verify the revised wording in the settings interface.

Written by the indexing model from the issue text.