Update Security String to 2019-05-01 in oc-m8-release
Bug: 128322951
(cherry picked from commit 9f8b89e4072bc5f1a93d796b6eec642737c93bc4)

Change-Id: Ifbe190132d7d6081e9fdc76207a88613ff6bd1cc
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 855993a..8ce30f6 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -181,7 +181,7 @@
     #  It must be of the form "YYYY-MM-DD" on production devices.
     #  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 := 2019-04-05
+      PLATFORM_SECURITY_PATCH := 2019-05-01
 endif
 
 ifndef PLATFORM_BASE_OS