Update Security String to 2019-09-05
Bug: 137199979
(cherry picked from commit ac6e24e5b1885981dfbc2297646aac9e29c37060)

Change-Id: Idcbf1d65f62266c1d744a103bec20b9fdc7ff737
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 9054c55..c264f75 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -250,7 +250,7 @@
     #  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 := 2019-09-01
+      PLATFORM_SECURITY_PATCH := 2019-09-05
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH