Bump Security String to 2020-09-05

Implemented:
============
CVE:            References:  Type:  Severity:  Updated AOSP versions:
CVE-2020-0074   A-146204120  EoP    High       8.0, 8.1, 9, 10
CVE-2020-0379   A-150156492  ID     High       8.0, 8.1, 9, 10
CVE-2020-0380   A-146398979  RCE    Critical   8.0, 8.1, 9, 10
CVE-2020-0381   A-150159669  ID     High       8.0, 8.1, 9, 10
CVE-2020-0382   A-152944488  ID     High       10
CVE-2020-0383   A-150160279  ID     High       8.0, 8.1, 9, 10
CVE-2020-0384   A-150159906  ID     High       8.0, 8.1, 9, 10
CVE-2020-0385   A-150160041  ID     High       8.0, 8.1, 9, 10
CVE-2020-0386   A-155650356  EoP    High       8.0, 8.1, 9, 10
CVE-2020-0388   A-156123285  EoP    High       10
CVE-2020-0389   A-156959408  ID     High       10
CVE-2020-0390   A-157598026  ID     High       10
CVE-2020-0391   A-158570769  EoP    High       9, 10
CVE-2020-0392   A-150226608  EoP    High       9, 10
CVE-2020-0393   A-154123412  ID     High       9, 10
CVE-2020-0394   A-155648639  EoP    High       8.0, 8.1, 9, 10
CVE-2020-0395   A-154124307  ID     High       8.0, 8.1, 9, 10
CVE-2020-0396   A-155094269  ID     Critical   8.0, 8.1, 9, 10
CVE-2020-0397   A-155092443  ID     High       8.0, 8.1, 9, 10
CVE-2020-0399   A-153993591  ID     High       8.0, 8.1, 9, 10
CVE-2020-0401   A-150857253  EoP    High       8.0, 8.1, 9, 10

Previously Implemented:
=======================
CVE:            References:  Type:  Severity:  Updated AOSP versions:
CVE-2020-0245   A-152496149  ID     High       10
                             RCE    Critical   8.0, 8.1, 9

Not Implemented:
================
None

Not Applicable (platform source):
=================================
None

Change-Id: I22fe42aa77ffb92f8dababcaf9ca1c6893fad606

Author: haggertk

core/version_defaults.mk

@@ -250,7 +250,7 @@ ifndef PLATFORM_SECURITY_PATCH
     #  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 := 2020-08-05
+      PLATFORM_SECURITY_PATCH := 2020-09-05
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH