Fix cpplint issues

Existing cpplint issues block uploading CLs, fix most of them.

Test: m checkbuild
Change-Id: I3477d388659c93c1ca517c4ad37502e0a71014ad
diff --git a/payload_generator/deflate_utils.h b/payload_generator/deflate_utils.h
index c055876..d69a551 100644
--- a/payload_generator/deflate_utils.h
+++ b/payload_generator/deflate_utils.h
@@ -17,9 +17,11 @@
 #ifndef UPDATE_ENGINE_PAYLOAD_GENERATOR_DEFLATE_UTILS_H_
 #define UPDATE_ENGINE_PAYLOAD_GENERATOR_DEFLATE_UTILS_H_
 
-#include <puffin/puffdiff.h>
+#include <string>
 #include <vector>
 
+#include <puffin/puffdiff.h>
+
 #include "update_engine/payload_generator/filesystem_interface.h"
 #include "update_engine/payload_generator/payload_generation_config.h"