AppStoreId property missing

Env:

* Operating System version: macOS Big Sur
* Firebase SDK version: 5.2.0
* Firebase Product: project_management
* Python version: 3.10
* Pip version: 21.1.2

Problem:

How can I create an iOS app with appStoreId using Project Management API ?

Firebase documentation (https://firebase.google.com/docs/projects/api/reference/rest/v1beta1/projects.iosApps#IosApp) contains definition of the iOSApp
`{
"name": string,
"appId": string,
"displayName": string,
"projectId": string,
"bundleId": string,
"appStoreId": string
}`
and states that creation request accepts instance of an iOSApp.

However method provided in the firebase_admin.project_management implementation provides ability to pass only bundle_id and display_name.

Start in the firebase_admin.project_management implementation, where iOS app creation currently accepts bundle_id and display_name. Trace the creation request and its tests, then add support for appStoreId and verify that the generated request includes it.

Written by the indexing model from the issue text.