Update Security String to 2023-04-01 am: 641c8e9c6b am: ac6cd2c238 am: af858ede19

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/21359394

Change-Id: Idee22c817ab2e2e047ce765e5a06a63cf290c811
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 856c693..a0b219f 100644
--- a/core/version_defaults.mk
+++ b/core/version_defaults.mk
@@ -240,7 +240,7 @@
     #  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 := 2023-03-01
+      PLATFORM_SECURITY_PATCH := 2023-04-01
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH