[ci-scan-net11] SafeArea keyboard layout tests repeatedly fail on Android API 36

## Summary
Two SafeArea keyboard layout tests repeatedly report that ContentGrid height does not shrink while the keyboard is shown on Android API 36.

## Build Information
- **Pipeline**: maui-pr-uitests
- **Build**: https://dev.azure.com/dnceng-public/public/_build/results?buildId=1586395
- **Build ID**: 1586395
- **Branch**: net11.0
- **First seen**: 2026-09-03
- **Occurrences**: 6 in last 10 builds

## Affected Legs
- Controls SafeAreaEdges / Android API 36 / Pixel 3 XL / CoreCLR

## Error Message
```
2026-09-07T20:16:54.0881577Z Failed SafeAreaNoWhiteSpaceAfterKeyboardDismissAndEdgeToggle [25 s]
ContentGrid should shrink when keyboard is showing with SafeAreaEdges=All
Expected: less than 2705
But was: 2705

2026-09-07T20:17:25.4002423Z Failed SafeAreaPerEdgeValidation [30 s]
ContentGrid height should be less when keyboard shows - MainGrid gets bottom padding from SoftInput
Expected: less than 2789
But was: 2789
```

## Investigation Context
The failures are in Issue28986_ContentPage.cs and Issue28986.cs under src/Controls/tests/TestCases.Shared.Tests/Tests/Issues. Both failures occur in the same Android SafeAreaEdges task and exercise ContentGrid sizing while soft input is visible. Five earlier builds in the window contain at least one of these failed test identities.

Start with Issue28986_ContentPage.cs and Issue28986.cs under src/Controls/tests/TestCases.Shared.Tests/Tests/Issues, then run the SafeAreaEdges Android API 36 tests on the maui-pr-uitests leg. Compare the keyboard-visible ContentGrid height with the expectations in SafeAreaNoWhiteSpaceAfterKeyboardDismissAndEdgeToggle and SafeAreaPerEdgeValidation; done means both tests reliably observe the expected shrinkage.

Written by the indexing model from the issue text.