config_tools: make acrn_configurator.py an executable script

Add the shebang header (for Python) and make the acrn_configurator.py
executable so it can more easily be run as in './acrn_configurator.py'

Tracked-On: #7057
Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>

misc/config_tools/config_app/acrn_configurator.py

@@ -1,3 +1,5 @@
+#!/usr/bin/env python3
+
 # Copyright (C) 2019 Intel Corporation.
 # SPDX-License-Identifier: BSD-3-Clause