EnsureCreated fails with CosmosDB if Scale not set

If you want to use the _EnsureCreated_ with a CosmosDB provider, the request fails with a generic 400 - BadRequest if the Cosmos instance does not have Scale setted.

To reproduce this, try to create a CosmosDB Database with _Provision throughput_ unselected and in your code (for example in the _Configure_ method of _Startup_ class, try to execute the code:

```C#
dbContext.Database.EnsureCreated();
```

If you create the database with the _Provision throughput_ selected and configured, the ensure works as expected.

EF Core version:
Database provider: Microsoft.EntityFrameworkCore.Cosmos v.5.0.10 and 5.0.12
Target framework: .NET 5.0
Operating system: Windows 10
IDE: Visual Studio 2019 16.11.7