Update SPL to 2021-12-01 am: ec6022f2e5 am: 38b8a44db6 am: 48181f100e am: 822db71705

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/16009632

Change-Id: I7e29a87a03bea575453235ccdf6d391e7dc91a60
diff --git a/core/version_defaults.mk b/core/version_defaults.mk
index 219f73b..892789f 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 := 2021-11-01
+      PLATFORM_SECURITY_PATCH := 2021-12-01
 endif
 .KATI_READONLY := PLATFORM_SECURITY_PATCH