[DO NOT MERGE] Updating Security String to 2017-03-01 on mnc-dev

b/34345751

Change-Id: I135c327aa611e92775966c4960f9da6e2aa95ed9
(cherry picked from commit a0cf89a0a06badf0bbf1dda6226df238afcf3972)
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 6c617d6..55ccde7 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -105,7 +105,7 @@
   #  It must match one of the Android Security Patch Level strings of the Public Security Bulletins.
   #
   #  If there is no $PLATFORM_SECURITY_PATCH set, keep it empty.
-  PLATFORM_SECURITY_PATCH := 2017-02-05
+  PLATFORM_SECURITY_PATCH := 2017-03-01
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"