EnableAotAnalyzer by default for src libraries (dotnet/runtime#81608)

* EnableAotAnalyzer by default for src libraries

This flips the default of EnableAotAnalyzer to true so all new libraries are analyzed by default. It also allows us to easily see which libraries haven't been annotated yet.

I also fixed the warnings in 2 libraries that were really quick: System.Memory.Data and System.ComponentModel.TypeConverter.

Contributes to dotnet/runtime#75480

Commit migrated from dotnet/runtime@ea7e1c7

Author: eerhardt

src/System.Drawing.Common/src/System.Drawing.Common.csproj

@@ -4,6 +4,7 @@
     <DefineConstants>$(DefineConstants);DRAWING_NAMESPACE</DefineConstants>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <WarningsNotAsErrors>CS0618</WarningsNotAsErrors>
+    <EnableAOTAnalyzer>false</EnableAOTAnalyzer>
     <IsPartialFacadeAssembly>true</IsPartialFacadeAssembly>
     <IsPackable>true</IsPackable>
     <AddXamarinPlaceholderFilesToPackage>true</AddXamarinPlaceholderFilesToPackage>