Allow zip64 support when opening zip files

When opening an zip file through zipfile.ZipFile(), python2 by default
disables zip64 support. To support update files >4GB, we manually add
allowZip64 to override the setting.

Test: generate && serve an OTA

Change-Id: I9645e963ced830cc2d3a4b72bc63b9369a1cefe8
diff --git a/tools/releasetools/test_utils.py b/tools/releasetools/test_utils.py
index 7b7f22a..ccd97a9 100755
--- a/tools/releasetools/test_utils.py
+++ b/tools/releasetools/test_utils.py
@@ -199,7 +199,7 @@
   @staticmethod
   def construct_zip_package(entries):
     zip_file = common.MakeTempFile(suffix='.zip')
-    with zipfile.ZipFile(zip_file, 'w') as zip_fp:
+    with zipfile.ZipFile(zip_file, 'w', allowZip64=True) as zip_fp:
       for entry in entries:
         zip_fp.writestr(
             entry,