avifImageDump: Declare the avif parameter as const

Also declare the decoder parameter of avifContainerDump() as const.
diff --git a/apps/shared/avifutil.c b/apps/shared/avifutil.c
index 4721b8d..f6657a1 100644
--- a/apps/shared/avifutil.c
+++ b/apps/shared/avifutil.c
@@ -120,13 +120,13 @@
     printf(" * Progressive    : %s\n", avifProgressiveStateToString(progressiveState));
 }
 
-void avifImageDump(avifImage * avif, uint32_t gridCols, uint32_t gridRows, avifProgressiveState progressiveState)
+void avifImageDump(const avifImage * avif, uint32_t gridCols, uint32_t gridRows, avifProgressiveState progressiveState)
 {
     const avifBool alphaPresent = avif->alphaPlane && (avif->alphaRowBytes > 0);
     avifImageDumpInternal(avif, gridCols, gridRows, alphaPresent, progressiveState);
 }
 
-void avifContainerDump(avifDecoder * decoder)
+void avifContainerDump(const avifDecoder * decoder)
 {
     avifImageDumpInternal(decoder->image, 0, 0, decoder->alphaPresent, decoder->progressiveState);
 }
diff --git a/apps/shared/avifutil.h b/apps/shared/avifutil.h
index 29a6087..8e0b1b5 100644
--- a/apps/shared/avifutil.h
+++ b/apps/shared/avifutil.h
@@ -28,8 +28,8 @@
 #define AVIF_FMT_ZU "%zu"
 #endif
 
-void avifImageDump(avifImage * avif, uint32_t gridCols, uint32_t gridRows, avifProgressiveState progressiveState);
-void avifContainerDump(avifDecoder * decoder);
+void avifImageDump(const avifImage * avif, uint32_t gridCols, uint32_t gridRows, avifProgressiveState progressiveState);
+void avifContainerDump(const avifDecoder * decoder);
 void avifPrintVersions(void);
 void avifDumpDiagnostics(const avifDiagnostics * diag);
 int avifQueryCPUCount(void); // Returns 1 if it cannot query or fails to query