Update Security String to 2021-01-01 am: 6441bc7ca3 am: cc0c1b00b6 am: 0f0c87eab7 am: e414401471 am: e4ca3c2ecf

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/13074489

Change-Id: I3ae8240a83bf652ab60d3b32d94065be36b1121b
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 721486c..251f2a8 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 := 2020-12-01
+      PLATFORM_SECURITY_PATCH := 2021-01-01
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH