sha module is deprecated

This patch removes the deprecated warnings from the python
scripts.

Change-Id: I052a0aab3fb28dd1d78de1307edafda6b6c35e5f
diff --git a/tools/releasetools/ota_from_target_files b/tools/releasetools/ota_from_target_files
index cd10d7c..78f37db 100755
--- a/tools/releasetools/ota_from_target_files
+++ b/tools/releasetools/ota_from_target_files
@@ -56,12 +56,16 @@
 import errno
 import os
 import re
-import sha
 import subprocess
 import tempfile
 import time
 import zipfile
 
+try:
+  from hashlib import sha1 as sha1
+except ImportError:
+  from sha import sha as sha1
+
 import common
 import edify_generator
 
@@ -318,7 +322,7 @@
   # we check to see if this recovery has already been installed by
   # testing just the first 2k.
   HEADER_SIZE = 2048
-  header_sha1 = sha.sha(recovery_img.data[:HEADER_SIZE]).hexdigest()
+  header_sha1 = sha1(recovery_img.data[:HEADER_SIZE]).hexdigest()
   sh = """#!/system/bin/sh
 if ! applypatch -c %(recovery_type)s:%(recovery_device)s:%(header_size)d:%(header_sha1)s; then
   log -t recovery "Installing new recovery image"
@@ -501,7 +505,7 @@
       verbatim_targets.append((tf.name, tf.size))
     else:
       common.ZipWriteStr(output_zip, "patch/" + tf.name + ".p", d)
-      patch_list.append((tf.name, tf, sf, tf.size, sha.sha(d).hexdigest()))
+      patch_list.append((tf.name, tf, sf, tf.size, sha1(d).hexdigest()))
       largest_source_size = max(largest_source_size, sf.size)
 
   source_fp = GetBuildProp("ro.build.fingerprint", source_zip)