As i believe we require to secure our domain & secure keys from users. I have R&D & found some solution/place where we can write these keys.
1) Values Folder [80% Security]: We can write these key in Values folder under the String.xml, as we have found when you use APK tool & de-compile the code then this folder is not visible to users but i have mentioned it's 80% Security because i have reviewed the some of thread & it's say we can retrieve the values folder too.
My Experience : Still i didn't found that it's accessible. you can use
2) C++ code[100% Security]: you can write your all the keys in C++ code & you can use. It will not accessible & de-compilable for other user.
