Use zipalign -p to page align .so files

Bug: 21400810
Change-Id: Ie3adf26dd3a51acfdb0faa23dc8ca1b206fb3727
(cherry picked from commit 903186f938a447e459720f6825382470ebb77e37)
diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 682dc45..f54c8bd 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -544,7 +544,7 @@
     raise ExternalError("signapk.jar failed: return code %s" % (p.returncode,))
 
   if align:
-    p = Run(["zipalign", "-f", str(align), sign_name, output_name])
+    p = Run(["zipalign", "-f", "-p", str(align), sign_name, output_name])
     p.communicate()
     if p.returncode != 0:
       raise ExternalError("zipalign failed: return code %s" % (p.returncode,))