Add XML documentation for Org.Apache.Http.Conn.Ssl

The `Org.Apache.Http.Conn.Ssl` namespace contains **20** `To be added` placeholders in source XML documentation (excluding `docs\xml\index.xml`).

```powershell
rg -n -i --glob 'Org.Apache.Http.Conn.Ssl/**' --glob 'ns-Org.Apache.Http.Conn.Ssl.xml' 'to be added' docs\xml
```

## Update log

- 2026-09-10: Refreshed the placeholder scan from **73** to **20** (reduced by **53**). Related documentation PRs: [#520](https://github.com/dotnet/android-api-docs/pull/520), [#622](https://github.com/dotnet/android-api-docs/pull/622), [#644](https://github.com/dotnet/android-api-docs/pull/644).

Start by running the provided rg command in docs\xml to locate the 20 remaining `To be added` placeholders under Org.Apache.Http.Conn.Ssl, excluding docs\xml\index.xml. Read the matching XML documentation entries and replace each placeholder with appropriate documentation; done means the namespace scan reports no remaining placeholders.039

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