Modernize Java source and clean up imports

* Refactor CameraActivity to use lambdas for UI listeners and fix precision in slider positioning.
* Modernize NDKHelper with text blocks and remove deprecated TargetApi annotations.
* Remove unused imports across modified Java files for better code health.

Author: Jake-The-Human

teapots/image-decoder/src/main/java/com/sample/helper/NDKHelper.java

@@ -16,36 +16,24 @@
 
 package com.sample.helper;
 
-import java.io.ByteArrayOutputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.nio.ByteBuffer;
-
-import javax.microedition.khronos.opengles.GL10;
-
-import android.R.bool;
-import android.opengl.GLES30;
-
-import android.annotation.TargetApi;
-import android.app.Activity;
 import android.app.NativeActivity;
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.graphics.Bitmap;
-import android.graphics.Bitmap.CompressFormat;
 import android.graphics.BitmapFactory;
 import android.graphics.Matrix;
 import android.media.AudioManager;
 import android.media.AudioTrack;
 import android.opengl.GLUtils;
 import android.os.Build;
 import android.util.Log;
-import android.view.View;
-import android.view.View.MeasureSpec;
+import java.io.File;
+import java.io.FileInputStream;
+import java.nio.ByteBuffer;
+import javax.microedition.khronos.opengles.GL10;
 
-@TargetApi(Build.VERSION_CODES.GINGERBREAD)
 public class NDKHelper {
 
     public NDKHelper(NativeActivity act) {
@@ -107,7 +95,7 @@ private Bitmap scaleBitmap(Bitmap bitmapToScale, float newWidth,
                 true);
     }
 
-    public class TextureInformation {
+    public static class TextureInformation {
         boolean ret;
         boolean alphaChannel;
         int originalWidth;

teapots/image-decoder/src/main/java/com/sample/imagedecoder/TeapotApplication.java

@@ -16,17 +16,10 @@
 
 package com.sample.imagedecoder;
 
-import javax.microedition.khronos.opengles.GL10;
-
 import android.app.Application;
-import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.graphics.Matrix;
-import android.opengl.GLUtils;
 import android.util.Log;
 import android.widget.Toast;