Expose mobile_side_only flags through the Server SDK

[0xarvin]

Describe the solution you'd like
When fetching all_flags_details, I noticed that FlagDetailConfig includes a field for client_side_only but it doesn't include one for mobile_side_only. We'd like to fetch the mobile only flags from our server. Our target architecture is to have the server drive a lot of the interactions with external vendors and for the client to require as few external dependencies as possible.

Describe alternatives you've considered
There are no additional pieces of information to discern flags from the returned values in all_flag_details. Otherwise, I would look through each of the flags and filter on whether it was a mobile only flag.

Additional context
Add any other context about the feature request here.

[cwaldren-ld]

Hi @0xarvin , this sounds like a reasonable use-case - would you mind expanding a bit on:

Our target architecture is to have the server drive a lot of the interactions with external vendors and for the client to require as few external dependencies as possible.

And how that relates to your request?

Filed internally as 236815.

[0xarvin]

So we don't want to use the LaunchDarkly iOS and Android SDKs. Rather, we want our server backend to retrieve the relevant mobile flags and return them to the client.

Right now, that isn't possible through any of the SDK endpoints.