style: fix Checkstyle violations (utility constructor, braces, imports)

Author: ligiastalves

src/main/java/com/thealgorithms/puzzlesandgames/RockPaperScissors.java

@@ -19,6 +19,10 @@
  */
 public class RockPaperScissors {
 
+    private RockPaperScissors() {
+        throw new UnsupportedOperationException("Utility class");
+    }
+
     public static void main(String[] args) {
         Scanner scanner = new Scanner(System.in);
         Random random = new Random();
@@ -60,8 +64,9 @@ public static String getResult(String userChoice, String computerChoice) {
             return "It's a tie!";
         } else if ((userChoice.equals("rock") && computerChoice.equals("scissors")) || (userChoice.equals("scissors") && computerChoice.equals("paper")) || (userChoice.equals("paper") && computerChoice.equals("rock"))) {
             return "You win! :D ";
-        } else
+        } else {
             return "You lose! :( ";
+        }
     }
     public static String getRandomChoice() {
         String[] options = {"rock", "paper", "scissors"};

src/test/java/com/thealgorithms/puzzlesandgames/RockPaperScissorsTest.java

@@ -1,5 +1,6 @@
 package com.thealgorithms.puzzlesandgames;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
 import org.junit.jupiter.api.Test;