Update Security String to 2021-03-01 am: 0e3ba7d2f7

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/13318721

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I409580bb0eeb98a17ca9791d42d8076e8721eb2d
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index ca000fa..7f1f18c 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -231,7 +231,7 @@
     #  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 := 2021-02-01
+      PLATFORM_SECURITY_PATCH := 2021-03-01
 endif
 
 ifndef PLATFORM_SECURITY_PATCH_TIMESTAMP