Added OOP Concepts Demonstration (Abstraction, Encapsulation, Inheritance, Polymorphism)

[SURYANSHUAGRAWAL2006]

Overview

This pull request adds a new oops package demonstrating the four core Object-Oriented Programming (OOP) principles:

• Abstraction
• Encapsulation
• Inheritance
• Polymorphism

Details

• Added clean, modular Java classes under the package com.thealgorithms.oops.
• Each concept is implemented with a simple, easy-to-understand real-world example.
• Followed Java conventions and TheAlgorithms project structure.
• All files compile and run successfully.

Why This Is Useful

This contribution helps learners understand OOP fundamentals through simple, executable code.
It aligns with the repository’s educational goal of providing clear algorithmic and programming examples.

Files Added

• AbstractionDemo.java
• EncapsulationDemo.java
• InheritanceDemo.java
• PolymorphismDemo.java

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Notes

All classes are independent and demonstrate their respective OOP principles.
Each example is concise, readable, and tested locally.

[SURYANSHUAGRAWAL2006]

Hi maintainers,
I have added Java examples for core OOP concepts in the new oops package. Please review this PR when convenient. Participating via Hacktoberfest. Thanks for your time.

[github-actions]

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