Python tool may run from source as the dos batch files. So, update python
code to call external tools with shell true mode.
Cc: Yonghong Zhu <yonghong.zhu@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Cc: Erik Bjorge <erik.c.bjorge@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Liming Gao <liming.gao@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Erik Bjorge <erik.c.bjorge@intel.com>
71f5913eb9