Update Face Detection Tutorial region tags to standard (#1201)

Author: alixhami

vision/face-detection/src/main/java/com/google/cloud/vision/samples/facedetect/FaceDetectApp.java

@@ -16,8 +16,7 @@
 
 package com.google.cloud.vision.samples.facedetect;
 
-// [BEGIN import_libraries]
-
+// [START vision_face_detection_tutorial_imports]
 import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
 import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
 import com.google.api.client.json.JsonFactory;
@@ -45,7 +44,7 @@
 import java.security.GeneralSecurityException;
 import java.util.List;
 import javax.imageio.ImageIO;
-// [END import_libraries]
+// [END vision_face_detection_tutorial_imports]
 
 /**
  * A sample application that uses the Vision API to detect faces in an image.
@@ -60,7 +59,7 @@ public class FaceDetectApp {
 
   private static final int MAX_RESULTS = 4;
 
-  // [START main]
+  // [START vision_face_detection_tutorial_run_application]
   /**
    * Annotates an image using the Vision API.
    */
@@ -85,9 +84,9 @@ public static void main(String[] args) throws IOException, GeneralSecurityExcept
     System.out.printf("Writing to file %s\n", outputPath);
     app.writeWithFaces(inputPath, outputPath, faces);
   }
-  // [END main]
+  // [END vision_face_detection_tutorial_run_application]
 
-  // [START get_vision_service]
+  // [START vision_face_detection_tutorial_client]
   /**
    * Connects to the Vision API using Application Default Credentials.
    */
@@ -99,7 +98,7 @@ public static Vision getVisionService() throws IOException, GeneralSecurityExcep
             .setApplicationName(APPLICATION_NAME)
             .build();
   }
-  // [END get_vision_service]
+  // [END vision_face_detection_tutorial_client]
 
   private final Vision vision;
 
@@ -110,7 +109,7 @@ public FaceDetectApp(Vision vision) {
     this.vision = vision;
   }
 
-  // [START detect_face]
+  // [START vision_face_detection_tutorial_send_request]
   /**
    * Gets up to {@code maxResults} faces for an image stored at {@code path}.
    */
@@ -141,9 +140,9 @@ public List<FaceAnnotation> detectFaces(Path path, int maxResults) throws IOExce
     }
     return response.getFaceAnnotations();
   }
-  // [END detect_face]
+  // [END vision_face_detection_tutorial_send_request]
 
-  // [START highlight_faces]
+  // [START vision_face_detection_tutorial_process_response]
   /**
    * Reads image {@code inputPath} and writes {@code outputPath} with {@code faces} outlined.
    */
@@ -176,5 +175,5 @@ private static void annotateWithFace(BufferedImage img, FaceAnnotation face) {
     gfx.setColor(new Color(0x00ff00));
     gfx.draw(poly);
   }
-  // [END highlight_faces]
+  // [END vision_face_detection_tutorial_process_response]
 }