Add Java Client to Server Streaming Section to SignalR Streaming Doc

Copy from #14261 by @mikaelm12

We need to add a small section for client to server streaming in Java.

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#### Document Details

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* ID: a02b4e7d-971a-670b-02eb-89c5456ec8f2
* Version Independent ID: 5f2f089e-310d-83a1-9c56-9cb441b9914a
* Content: [Use streaming in ASP.NET Core SignalR](https://docs.microsoft.com/en-us/aspnet/core/signalr/streaming?view=aspnetcore-2.2)
* Content Source: [aspnetcore/signalr/streaming.md](https://github.com/aspnet/AspNetCore.Docs/blob/master/aspnetcore/signalr/streaming.md)
* Product: **aspnet-core**
* Technology: **aspnetcore-signalr**
* GitHub Login: @bradygaster
* Microsoft Alias: **bradyg**