fix: remove main method and add unit tests for StringRotation

Author: konduri-lakshmi-prasanna

src/main/java/com/thealgorithms/strings/StringRotation.java

@@ -1,11 +1,13 @@
 package com.thealgorithms.strings;
 
-import java.util.Scanner;
-
+/**
+ * Checks if one string is a rotation of another string.
+ */
 public class StringRotation {
 
     /**
-     * Checks if str2 is a rotation of str1
+     * Checks if str2 is a rotation of str1.
+     *
      * @param str1 Original string
      * @param str2 String to check for rotation
      * @return true if str2 is a rotation of str1, false otherwise
@@ -22,24 +24,4 @@ public static boolean isRotation(String str1, String str2) {
         String concatenated = str1 + str1;
         return concatenated.contains(str2);
     }
-
-    public static void main(String[] args) {
-        Scanner scanner = new Scanner(System.in);
-
-        System.out.print("Enter first string: ");
-        String str1 = scanner.nextLine();
-
-        System.out.print("Enter second string: ");
-        String str2 = scanner.nextLine();
-
-        boolean result = isRotation(str1, str2);
-
-        if (result) {
-            System.out.println("\"" + str2 + "\" is a rotation of \"" + str1 + "\".");
-        } else {
-            System.out.println("\"" + str2 + "\" is NOT a rotation of \"" + str1 + "\".");
-        }
-
-        scanner.close();
-    }
 }