feat: fix checkstyle issues

Author: sailok.chinta

src/main/java/com/thealgorithms/tries/Trie.java

@@ -10,7 +10,7 @@ class TrieNode {
     private char letter;
     private boolean end;
 
-    public TrieNode(char letter) {
+    TrieNode(char letter) {
         this.letter = letter;
         this.children = new TrieNode[CHILDREN_NODE_COUNT];
         this.end = false;

src/test/java/com/thealgorithms/tries/TrieTest.java

@@ -5,10 +5,10 @@
 import org.junit.jupiter.api.Test;
 
 public class TrieTest {
-    private static List<String> WORDS = List.of("apple", "app", "rest", "rent", "rental");
+    private static final List<String> WORDS = List.of("apple", "app", "rest", "rent", "rental");
 
     @Test
-    void searchInTrie_success() {
+    void searchInTrieSuccess() {
         Trie trie = new Trie();
 
         for (String word : WORDS) {
@@ -21,7 +21,7 @@ void searchInTrie_success() {
     }
 
     @Test
-    void startsWithPrefixInTrie_success() {
+    void startsWithPrefixInTrieSuccess() {
         Trie trie = new Trie();
 
         for (String word : WORDS) {