Add XML documentation for Android.Net.Wifi.P2p

The `Android.Net.Wifi.P2p` namespace contains **831** `To be added` placeholders in source XML documentation (excluding `docs\xml\index.xml`).

Example command:

```powershell
rg -n -i --glob 'Android.Net.Wifi.P2p/**' --glob 'ns-Android.Net.Wifi.P2p.xml' 'to be added' docs\xml
```

## Update log

- 2026-09-10: Refreshed the placeholder scan from **794** to **831** (increased by **37**). Related documentation PRs: [#644](https://github.com/dotnet/android-api-docs/pull/644).

Start by running the provided rg command against docs\xml to enumerate the Android.Net.Wifi.P2p source XML documentation files and their 831 `To be added` placeholders, excluding docs\xml\index.xml. Replace the placeholders with appropriate documentation for the affected API entries, and rerun the scan to confirm none remain.

Vom Indexierungsmodell aus dem Issue-Text verfasst.