Revert "Update Security String from 08-05 to 2019-08-01 Bug:126590667"

This reverts commit ef7c2c79154126902194b1bb6bf166b7e201bc83.

Reason for revert: Resolve string downgrade issue

Change-Id: I28831f2592bba09907b76c7d5ac46326a9c1e9f8
(cherry picked from commit 0c355124bf6681d51a93d32a56519c1e3560b503)

core/version_defaults.mk

diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 01d72dc..c8792e9 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 := 2019-08-01
+      PLATFORM_SECURITY_PATCH := 2019-08-05
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH