Update free-courses-en.md (#8548)

* Update free-courses-en.md 

Added a Java DSA course.

* Update free-courses-en.md

Co-authored-by: Eric Hellman <eric@hellman.net>

courses/free-courses-en.md

@@ -151,6 +151,7 @@
 * [Data Structures and Algorithms](https://youtube.com/playlist?list=PLBZBJbE_rGRV8D7XZ08LK6z-4zPoWzu5H) - CS Dojo
 * [Data Structures and Algorithms](https://www.youtube.com/playlist?list=PLdo5W4Nhv31bbKJzrsKfMpo_grxuLl8LU) - Jenny's lectures CS/IT NET&JRF
 * [Data Structures and Algorithms](https://techdevguide.withgoogle.com/paths/data-structures-and-algorithms/?no-filter=true) - Tech Dev Guide by Google
+* [Data Structures And Algorithms DSA In JAVA Full Course](https://www.youtube.com/playlist?list=PLrk5tgtnMN6StFV60jlQ9W-RXyHppbp8G) - Coding Ninjas
 * [Data Structures and Algorithms for Beginners](https://www.youtube.com/watch?v=BBpAmxU_NQo) - Mosh Hamedani (Programming with Mosh)
 * [Data Structures and Algorithms Full Course](https://www.youtube.com/watch?v=LcKqYoX8uH4) - Simplilearn (YouTube, Video length 7:13:56)
 * [Data Structures and Algorithms in Java Full Course](https://youtube.com/playlist?list=PL6Zs6LgrJj3tDXv8a_elC6eT_4R5gfX4d) - Dinesh Varyani (YouTube playlist)