Clean up unit test MSBuild information

Couple of changes

- Advertise the UnitTestContainer capability
- Remove the now unnecessary legacy F5 settings for xunit procesess

build/Targets/Imports.targets

@@ -41,11 +41,6 @@
         <CopyNuGetImplementations>false</CopyNuGetImplementations>
         <OutputPath>$(OutputPath)Dlls\$(MSBuildProjectName)\</OutputPath>
       </PropertyGroup>
-
-      <!-- Add the UnitTestContainer project capability -->
-      <ItemGroup>
-        <ProjectCapability Include="UnitTestContainer" />
-      </ItemGroup>
     </When>
     <When Condition="'$(RoslynProjectType)' == 'CompilerGeneratorTool'">
       <PropertyGroup>
@@ -208,6 +203,11 @@
     <_ExplicitReference Include="$(FrameworkPathOverride)\mscorlib.dll" />
   </ItemGroup>
 
+  <!-- Add the UnitTestContainer project capability -->
+  <ItemGroup Condition="'$(_IsAnyUnitTest)' == 'true'">
+    <ProjectCapability Include="UnitTestContainer" />
+  </ItemGroup>
+
   <ItemDefinitionGroup Condition="'$(_CopyReferences)' == 'false'">
     <Reference>
       <Private>False</Private>

build/Targets/Roslyn.Toolsets.Xunit.targets

@@ -6,12 +6,6 @@
     <XUnitPath>$(NuGetPackageRoot)\xunit.runner.console\$(xunitrunnerconsoleVersion)\tools\xunit.console.x86.exe</XUnitPath>
     <XUnitTestResultsDirectory>$(OutDir)\xUnitResults</XUnitTestResultsDirectory>
     <XUnitArguments>"$(OutDir)\$(AssemblyName).dll" -html "$(XUnitTestResultsDirectory)\$(AssemblyName).html" -noshadow</XUnitArguments>
-
-    <!-- These properties are ignored by CPS projects, which use launchSettings.json instead. -->
-    <StartAction Condition="'$(StartActions)' == ''">Program</StartAction>
-    <StartProgram Condition="'$(StartProgram)' == ''">$(XUnitPath)</StartProgram>
-    <StartArguments Condition="'$(StartArguments)' == ''">$(XUnitArguments)</StartArguments>
-
     <PrepareForBuildDependsOn>$(PrepareForBuildDependsOn);AddDefaultTestAppConfig</PrepareForBuildDependsOn>
   </PropertyGroup>