Android: fixes build NDK 21d
diff --git a/src/audio/aaudio/SDL_aaudio.h b/src/audio/aaudio/SDL_aaudio.h
index 2b16fb1..494e827 100644
--- a/src/audio/aaudio/SDL_aaudio.h
+++ b/src/audio/aaudio/SDL_aaudio.h
@@ -24,6 +24,7 @@
#define _SDL_aaudio_h
#include "../SDL_sysaudio.h"
+#include <stdbool.h>
#include <aaudio/AAudio.h>
/* Hidden "this" pointer for the audio functions */