Add XML documentation for Android.Net.Wifi.Aware

The `Android.Net.Wifi.Aware` namespace contains **529** `To be added` placeholders in source XML documentation (excluding `docs\xml\index.xml`).

Example command:

```powershell
rg -n -i --glob 'Android.Net.Wifi.Aware/**' --glob 'ns-Android.Net.Wifi.Aware.xml' 'to be added' docs\xml
```

## Update log

- 2026-09-10: Refreshed the placeholder scan from **505** to **529** (increased by **24**). Related documentation PRs: [#644](https://github.com/dotnet/android-api-docs/pull/644).

Run the provided rg command against docs\xml to list the 529 `To be added` placeholders under Android.Net.Wifi.Aware, then inspect the matching source XML documentation entries. Use the surrounding API names and existing documentation patterns as the starting point. Done means the namespace’s placeholders are replaced with useful XML documentation, excluding docs\xml\index.xml.

Written by the indexing model from the issue text.