SDL: Added note for Android 12 API level

From c948b9366c660057bf5cc831f8fe75899a8f0396 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Tue, 2 Nov 2021 15:57:24 -0700
Subject: [PATCH] Added note for Android 12 API level

---
 include/SDL_system.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/SDL_system.h b/include/SDL_system.h
index 423c4c3c83..8910d3fa76 100644
--- a/include/SDL_system.h
+++ b/include/SDL_system.h
@@ -262,6 +262,7 @@ extern DECLSPEC void * SDLCALL SDL_AndroidGetActivity(void);
 /**
  * Query Android API level of the current device.
  *
+ * - API level 31: Android 12
  * - API level 30: Android 11
  * - API level 29: Android 10
  * - API level 28: Android 9