Initialize the VsTestUseConsole property during acceptance tests

The `$(VSTestUseConsole)` should be set to `True` when running the `dotnet test` command to keep the legacy behavior. Adding it during the tests for now: it should be set in the command itself eventually.

test/Microsoft.TestPlatform.TestUtilities/IntegrationTestBase.cs

@@ -197,6 +197,9 @@ public void InvokeDotnetTest(string arguments, Dictionary<string, string?>? envi
 
         var vstestConsolePath = GetDotnetRunnerPath();
 
+        //TODO: set this property by default in the dotnet test command (cf. https://github.com/microsoft/vstest/pull/2702)
+        debugEnvironmentVariables["VsTestUseConsole"] = "True";
+
         if (arguments.Contains(".csproj"))
         {
             arguments += $@" -p:VsTestConsolePath=""{vstestConsolePath}""";