Don't close file descriptors when starting python program

Python programs run via a wrapper script. That wrapper script
can be started with open file descriptors, for example by using
the <(echo foo) syntax in bash. The shouldn't be closed when
starting the real script.

Bug: 203436762
Test: Presubmits
Change-Id: Ib20450f713b15c8a5527d1e433bfd9635cead85f

python/scripts/stub_template_host.txt

@@ -81,7 +81,9 @@ def Main():
     os.environ.update(new_env)
 
     sys.stdout.flush()
-    retCode = subprocess.call(args)
+    # close_fds=False so that you can run binaries with files provided on the command line:
+    # my_python_app --file <(echo foo)
+    retCode = subprocess.call(args, close_fds=False)
     sys.exit(retCode)
   except:
     raise