Add XML documentation for Android.Views.Translation

The `Android.Views.Translation` namespace contains **417** `To be added` placeholders in source XML documentation (excluding `docs\xml\index.xml`).

```powershell
rg -n -i --glob 'Android.Views.Translation/**' --glob 'ns-Android.Views.Translation.xml' 'to be added' docs\xml
```

## Update log

- 2026-09-10: Refreshed the placeholder scan from **429** to **417** (reduced by **12**). Related documentation PRs: [#360](https://github.com/dotnet/android-api-docs/pull/360), [#432](https://github.com/dotnet/android-api-docs/pull/432), [#607](https://github.com/dotnet/android-api-docs/pull/607), [#644](https://github.com/dotnet/android-api-docs/pull/644).

Run the issue's rg scan against docs\xml to enumerate the Android.Views.Translation source XML entries, excluding docs\xml\index.xml. Read the matching documentation blocks and replace the 417 “To be added” placeholders with accurate content; rerun the scan and confirm none remain.

Vom Indexierungsmodell aus dem Issue-Text verfasst.