DO NOT MERGE: Only use a fixed timestamp when packaging.

This CL changes to use a fixed timestamp only when packaging
into the target_files zip.

Bug: 24377993
Change-Id: I01d136f4b99e1eff80c559192d93db83a3c5c0a4
(cherry picked from commit 822f5840c0f498e33829a0a00f383d9be3a7e913)
diff --git a/tools/releasetools/add_img_to_target_files.py b/tools/releasetools/add_img_to_target_files.py
index f7332b2..f2bf1e1 100755
--- a/tools/releasetools/add_img_to_target_files.py
+++ b/tools/releasetools/add_img_to_target_files.py
@@ -28,6 +28,7 @@
   print >> sys.stderr, "Python 2.7 or newer is required."
   sys.exit(1)
 
+import datetime
 import errno
 import os
 import tempfile
@@ -122,6 +123,12 @@
   if fstab:
     image_props["fs_type"] = fstab["/" + what].fs_type
 
+  # Use a fixed timestamp (01/01/2009) when packaging the image.
+  # Bug: 24377993
+  epoch = datetime.datetime.fromtimestamp(0)
+  timestamp = (datetime.datetime(2009, 1, 1) - epoch).total_seconds()
+  image_props["timestamp"] = int(timestamp)
+
   if what == "system":
     fs_config_prefix = ""
   else:
@@ -173,6 +180,12 @@
 
   print "creating userdata.img..."
 
+  # Use a fixed timestamp (01/01/2009) when packaging the image.
+  # Bug: 24377993
+  epoch = datetime.datetime.fromtimestamp(0)
+  timestamp = (datetime.datetime(2009, 1, 1) - epoch).total_seconds()
+  image_props["timestamp"] = int(timestamp)
+
   # The name of the directory it is making an image out of matters to
   # mkyaffs2image.  So we create a temp dir, and within it we create an
   # empty dir named "data", and build the image from that.
@@ -210,6 +223,12 @@
 
   print "creating cache.img..."
 
+  # Use a fixed timestamp (01/01/2009) when packaging the image.
+  # Bug: 24377993
+  epoch = datetime.datetime.fromtimestamp(0)
+  timestamp = (datetime.datetime(2009, 1, 1) - epoch).total_seconds()
+  image_props["timestamp"] = int(timestamp)
+
   # The name of the directory it is making an image out of matters to
   # mkyaffs2image.  So we create a temp dir, and within it we create an
   # empty dir named "cache", and build the image from that.
diff --git a/tools/releasetools/build_image.py b/tools/releasetools/build_image.py
index 4b43c0c..357a666 100755
--- a/tools/releasetools/build_image.py
+++ b/tools/releasetools/build_image.py
@@ -399,6 +399,7 @@
     mount_point: such as "system", "data" etc.
   """
   d = {}
+
   if "build.prop" in glob_dict:
     bp = glob_dict["build.prop"]
     if "ro.build.date.utc" in bp: