Hide variable value

Hide variable value

I'm writing a small Android app and I need to hide some variable values. I
have a API key I got from the content provider who is providing me content
to show in my app that I need to retrieve data from them. Because it is
being used in an encryption algorithm, it is of vital importance the code
isn't leaked.
I need to save the API key in my code and be sure it isn't retrievable by
the bad people in the world. What I do now, is save them in my code as a
variable:
private static final String API_KEY="mysupersecreatapikey";
After the app is compiled to an APK file, this is, in my opinion not
retrievable anymore. Am I doing it in the right way now, or is there a
better solution?
Thx in advance, Daryl