[FR] Support Apple's location push type

[ChristianOrgler]

Is your feature request related to a problem? Please describe. Since iOS 15 was introduced by Apple we would like to support their new location push notification. FCM currently returns an error because it doesn't support the type.

Describe the solution you'd like FCM supporting the new location push type.

Describe alternatives you've considered Implementing the sending of location remote notifications on our own which disruptes the centralized way of how we send remote notifications.

Additional context

• Apple's documentation - see under Send Location Push Requests From Your Server
• GitHub Issue related incl. discussion with @chliangGoogle
• Firebase Feature Request Number: 10155562

[google-oss-bot]

I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.