Remove uses of SkImageDecoder from samplecode

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1812323003

Review URL: https://codereview.chromium.org/1812323003
diff --git a/samplecode/SampleCamera.cpp b/samplecode/SampleCamera.cpp
index b860917..ed6cc52 100644
--- a/samplecode/SampleCamera.cpp
+++ b/samplecode/SampleCamera.cpp
@@ -5,6 +5,7 @@
  * found in the LICENSE file.
  */
 
+#include "DecodeFile.h"
 #include "SampleCode.h"
 #include "SkAnimTimer.h"
 #include "SkView.h"
@@ -17,7 +18,6 @@
 #include "SkShader.h"
 #include "SkUtils.h"
 #include "SkRandom.h"
-#include "SkImageDecoder.h"
 
 class CameraView : public SampleView {
     SkTDArray<SkShader*> fShaders;
@@ -33,7 +33,7 @@
             SkString str;
             str.printf("/skimages/elephant%d.jpeg", i);
             SkBitmap bm;
-            if (SkImageDecoder::DecodeFile(str.c_str(), &bm)) {
+            if (decode_file(str.c_str(), &bm)) {
                 SkRect src = { 0, 0, SkIntToScalar(bm.width()), SkIntToScalar(bm.height()) };
                 SkRect dst = { -150, -150, 150, 150 };
                 SkMatrix matrix;