Fix some crashing tests

[mattleibow]

Description of Change

One test seemed to go bad after #4933 and that was because the PR did not catch the bad test. This is because of 2 reasons:

• We disabled the warnings in the IDE
  We have disabled the warnings because we have an API that we use that the analyzer did not know about. We are in the process of fixing this, but we went too far and turned off the warnings instead of downgrading to suggestions.
• We didn't actually test all the android levels
  We don't because there are a lot to test, but maybe we should have the latest and the oldest in the PR just to be safe. The runs are pretty quick on the accelerated bots, so this won't add much time.

Issues Fixed

A crashing test and total lack of warnings.

NOTE

I was unable to fix the tests on older Android devices, so I disabled them there and opened this issue: #5903

[mattleibow]

lol:

9>CSC : error AD0001: Analyzer 'Microsoft.NetCore.Analyzers.InteropServices.PlatformCompatibilityAnalyzer' threw an exception of type 'System.NullReferenceException' with message 'Object reference not set to an instance of an object.'. [D:\a_work\1\s\src\Essentials\src\Essentials.csproj]

[jsuarezruiz]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s), but failed to run 1 pipeline(s).

[mattleibow]

/azp run

[azure-pipelines]

Azure Pipelines successfully started running 2 pipeline(s).

[PureWeen]

https://tfsprodcus3.visualstudio.com/Ad0adf05a-e7d7-4b65-96fe-3f3884d42038/public/_TestManagement/Runs?runId=1498888&_a=resultSummary&resultId=100518

Fixed Tests

[rmarinho]

@mattleibow seems some tests failing on API23 .. CanLoadFonts

https://dev.azure.com/xamarin/public/_build/results?buildId=58210&view=ms.vss-test-web.build-test-results-tab

[mattleibow]

For some reason, the same font is loaded but with different handles on older devices. It is not default font, so it seems that it just loaded 2 of the same fonts n memory...