I read the instructions for using Java8 for android development from this answer and (orfjackal/retrolambda).
I wanted to know if it is a good practice to use this technique to implement Java 8. Does this affects the application performance?
It is mentioned in the blog- retrolambda It does this by transforming your Java 8 compiled bytecode so that it can run on an older Java runtime.
I think it is too early to say that use Java 8 is a good practice for android development, officially android needs the Java 6 JDK as mentioned at the bottom of this page: https://developer.android.com/sdk/installing/installing-adt.html
Also, there are some Android APIs that even not support try with resources, so I don't think they'll support Java 8 at all.