Cleanup name of test exclusion itemgroup (#50513)

Follow up from feedback in #50332

Author: akoeplinger

src/libraries/tests.proj

@@ -71,7 +71,7 @@
 
   <ItemGroup Condition="'$(TargetOS)' == 'Android' and '$(TargetArchitecture)' == 'x86'">
     <!-- https://github.com/dotnet/runtime/issues/50493 -->
-    <FunctionalTestExclusions Include="$(RepoRoot)\src\tests\FunctionalTests\Android\Device_Emulator\AOT\Android.Device_Emulator.Aot.Test.csproj" />
+    <ProjectExclusions Include="$(RepoRoot)\src\tests\FunctionalTests\Android\Device_Emulator\AOT\Android.Device_Emulator.Aot.Test.csproj" />
   </ItemGroup>
 
   <ItemGroup Condition="('$(TargetOS)' == 'iOS' or '$(TargetOS)' == 'iOSSimulator' or '$(TargetOS)' == 'tvOS' or '$(TargetOS)' == 'tvOSSimulator') and '$(RunDisablediOSTests)' != 'true'">
@@ -353,29 +353,29 @@
     <ProjectReference Include="$(MonoProjectRoot)sample\iOS\Program.csproj"
                       BuildInParallel="false" />
     <ProjectReference Include="$(RepoRoot)\src\tests\FunctionalTests\iOS\**\*.Test.csproj"
-                      Exclude="@(FunctionalTestExclusions)"
+                      Exclude="@(ProjectExclusions)"
                       BuildInParallel="false" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(ArchiveTests)' == 'true' and ('$(TargetOS)' == 'tvOS' or '$(TargetOS)' == 'tvOSSimulator')">
     <ProjectReference Include="$(RepoRoot)\src\tests\FunctionalTests\tvOS\**\*.Test.csproj"
-                      Exclude="@(FunctionalTestExclusions)"
+                      Exclude="@(ProjectExclusions)"
                       BuildInParallel="false" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(ArchiveTests)' == 'true' and '$(TargetOS)' == 'Android'">
     <ProjectReference Include="$(MonoProjectRoot)sample\Android\AndroidSampleApp.csproj"
                       BuildInParallel="false" />
     <ProjectReference Include="$(RepoRoot)\src\tests\FunctionalTests\Android\**\*.Test.csproj"
-                      Exclude="@(FunctionalTestExclusions)"
+                      Exclude="@(ProjectExclusions)"
                       BuildInParallel="false" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(ArchiveTests)' == 'true' and '$(TargetOS)' == 'Browser'">
     <ProjectReference Include="$(MonoProjectRoot)sample\wasm\**\*.Sample.csproj"
                       BuildInParallel="false" />
     <ProjectReference Include="$(RepoRoot)\src\tests\FunctionalTests\WebAssembly\**\*.Test.csproj"
-                      Exclude="@(FunctionalTestExclusions)"
+                      Exclude="@(ProjectExclusions)"
                       BuildInParallel="false" />
   </ItemGroup>