chore(release): address PR review comments on ReleaseNoteGeneration

Author: jinseopkim0

java-cloud-bom/release-note-generation/src/main/java/com/google/cloud/ReleaseNoteGeneration.java

@@ -34,9 +34,11 @@
 import com.google.common.collect.Sets;
 import com.google.common.collect.Sets.SetView;
 import com.google.common.collect.Streams;
-import com.google.common.io.Files;
 import java.io.File;
 import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
@@ -46,7 +48,6 @@
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import org.apache.commons.codec.Charsets;
 import org.eclipse.aether.RepositorySystem;
 import org.eclipse.aether.artifact.Artifact;
 import org.eclipse.aether.artifact.DefaultArtifact;
@@ -108,7 +109,7 @@ public static void main(String[] arguments)
     ReleaseNoteGeneration generation = new ReleaseNoteGeneration();
     String report = generation.generateReport(bom, googleCloudJavaVersion);
 
-    Files.asCharSink(new File(RELEASE_NOTE_FILE_NAME), Charsets.UTF_8).write(report);
+    Files.writeString(Path.of(RELEASE_NOTE_FILE_NAME), report);
     System.out.println("Wrote " + RELEASE_NOTE_FILE_NAME);
   }
 
@@ -645,7 +646,7 @@ static String fetchReleaseNote(String owner, String repository, String tag)
       throws IOException, InterruptedException {
     // gh release --repo googleapis/java-storage view v2.16.0
 
-    File tempFile = java.nio.file.Files.createTempFile("gh-release-notes", ".txt").toFile();
+    File tempFile = Files.createTempFile("gh-release-notes", ".txt").toFile();
     tempFile.deleteOnExit();
 
     Process process = null;
@@ -661,10 +662,7 @@ static String fetchReleaseNote(String owner, String repository, String tag)
         throw new IOException("The process timed out");
       }
 
-      String output =
-          new String(
-              java.nio.file.Files.readAllBytes(tempFile.toPath()),
-              java.nio.charset.StandardCharsets.UTF_8);
+      String output = new String(Files.readAllBytes(tempFile.toPath()), StandardCharsets.UTF_8);
 
       if (process.exitValue() != 0) {
         String trimmedOutput = output.trim();