Add start and stop commands to vm.sh's usage description
Add start and stop commands to vm.sh's usage description

Change-Id: I4e3dd8a1b6e252eddc28d01986735ae33fc175b9

bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration