distribtests_standalone: fixing nits

tools/dockerfile/push_testing_images.sh

@@ -29,7 +29,7 @@ cd -
 
 DOCKERHUB_ORGANIZATION=grpctesting
 
-for DOCKERFILE_DIR in tools/dockerfile/test/* tools/dockerfile/grpc_artifact_* tools/dockerfile/interoptest/* third_party/rake-compiler-dock
+for DOCKERFILE_DIR in tools/dockerfile/test/* tools/dockerfile/grpc_artifact_* tools/dockerfile/interoptest/* tools/dockerfile/distribtest/cpp_jessie_x64 third_party/rake-compiler-dock
 do
   # Generate image name based on Dockerfile checksum. That works well as long
   # as can count on dockerfiles being written in a way that changing the logical 

tools/internal_ci/windows/grpc_distribtests_standalone.bat

@@ -24,7 +24,7 @@ cd /d %~dp0\..\..\..
 
 call tools/internal_ci/helper_scripts/prepare_build_windows.bat
 
-python tools/run_tests/task_runner.py -f distribtests windows cpp -j 4 || goto :error
+python tools/run_tests/task_runner.py -f distribtest windows cpp -j 4 || goto :error
 goto :EOF
 
 :error