2796724: Support Python3

https://chromium-review.googlesource.com/c/infra/luci/python-adb/+/2796724

build/mac/make_locale_dirs.py

@@ -8,6 +8,7 @@
 # require any direct Cocoa locale support.
 
 import os
+import errno
 import sys
 
 
@@ -16,7 +17,7 @@ def main(args):
     try:
       os.makedirs(dirname)
     except OSError as e:
-      if e.errno == os.errno.EEXIST:
+      if e.errno == errno.EEXIST:
         # It's OK if it already exists
         pass
       else: