modify Module Subprocess32 to module subprocess

In Ambari 2.7.5, it use a module call "Subprocess32".

When I try to adapt Ambari from python2 to python3, I found that subprocess is a build-in module in python3. And in my opinion Ambari 2.7.5 import Subprocess32 in order to using the same function as python3's module subprocess. 

So I would like to change all "import Subprocess32" to "import subprocess" and check whether ambari can still work. 

The problem is that I am not sure Subprocess32 defined in Ambari 2.7.5 is actuually the same as python3.subprocess, Any suggestions? Welcome to discuss here and contribute to python3 adaption。