Update Security Strings to 2019-10-05

Bug:139434268
Change-Id: I063f0430347d9f1e6ea5a8133204585833ed5ddc
(cherry picked from commit 84633edb224bfc2d17807e61ce57db6d391c2230)
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index c264f75..43d4d3e 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 := 2019-09-05
+      PLATFORM_SECURITY_PATCH := 2019-10-05
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH