Update example string values for properties defined with date-time format

[gmuratk]

Problem description

It has been reported that some tool chains are having issues with string values without quotes for properties defined in date-time format.
In device-reachability-status-subscriptions.yaml and device-roaming-status-subscriptions.yaml properties startsAt, expiresAt, and subscriptionExpireTime cause such issue.

Expected behavior

Wrap all the examples of such properties in quotes in all of the API definitions.
Example:

    startsAt: 2024-07-03T21:12:02.871Z --> "2024-07-03T21:12:02.871Z"
    expiresAt: 2024-07-03T21:12:02.871Z --> "2024-07-03T21:12:02.871Z"

Alternative solution

Additional context

[sachinvodafone]

Hi @gmuratk, Nice catch !!! I am unable to recall but we have agreed to have single quote for String value like

startsAt: '2024-07-03T21:12:02.871Z'
expiresAt: '2024-07-03T21:12:02.871Z'

same has been used across all other APIs too

[eric-murray]

@sachinvodafone
It can be single or double quotes. Doesn't matter.