samples: Fixes checkstyle, 3P libs before java libs

Author: gguuss

vision/snippets/src/main/java/com/example/vision/Detect.java

@@ -34,14 +34,14 @@
 import com.google.cloud.vision.v1.SafeSearchAnnotation;
 import com.google.protobuf.ByteString;
 
+import org.joda.time.Duration;
+
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.PrintStream;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.joda.time.Duration;
-
 public class Detect {
 
   /**