[DO NOT MERGE] Update Security String to 2017-06-01 for mnc-dev

bug:37204197
Change-Id: I80259eef1e7a0d0761d3bb31082b7b3606cef669
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 7516a12..a2bb05b 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 := 2017-05-01
+  PLATFORM_SECURITY_PATCH := 2017-06-01
 endif
 
 ifeq "" "$(PLATFORM_BASE_OS)"