resource_extractor.py should preserve the timestamps of entries of the input JAR

RELNOTES:

--
MOS_MIGRATED_REVID=139370787
diff --git a/tools/android/resource_extractor.py b/tools/android/resource_extractor.py
index 5177d5e..2cd11d9 100644
--- a/tools/android/resource_extractor.py
+++ b/tools/android/resource_extractor.py
@@ -90,7 +90,7 @@
 def ExtractResources(input_jar, output_zip):
   for path in input_jar.namelist():
     if IsValidPath(path):
-      output_zip.writestr(path, input_jar.read(path))
+      output_zip.writestr(input_jar.getinfo(path), input_jar.read(path))
 
 
 def main(argv):