Add Java Course (#10328)

* Add Java Course

* Update free-courses-en.md

Did the suggested changes.

courses/free-courses-en.md

@@ -834,6 +834,7 @@
 * [Introduction to Java](http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-092-introduction-to-programming-in-java-january-iap-2010/)
 * [Introduction to Java + DSA](https://youtube.com/playlist?list=PL9gnSGHSqcnr_DxHsP7AW9ftq0AtAyYqJ) - Kunal Kushwaha
 * [Java Beginner](https://youtube.com/playlist?list=PLkeaG1zpPTHiMjczpmZ6ALd46VjjiQJ_8) - Coding with John
+* [Java Complete Course - Placement Series](https://www.youtube.com/playlist?list=PLfqMhTWNBTe3LtFWcvwpqTkUSlB32kJop) - Apna College
 * [Java Design Patterns and Architecture](https://www.udemy.com/course/java-design-patterns-tutorial) - John Purcell (Udemy)
 * [Java for Complete Beginners](http://courses.caveofprogramming.com/courses/java-for-complete-beginners)
 * [Java for Mobile Devices - Introducing Codename One](https://codenameone.teachable.com/p/java-for-mobile-devices-introducing-codename-one)