Not to bash your post or anything but in future I suggest you check your facts first, If you look around Medium you'll find a lot of similar blogs about securing secrets e.t.c pointing towards using NDK "to make it hard to de-compile" but as Jt has just pointed out, this technique does not assure security nor does it add much in the way of hardening sensitive information which all the aforementioned blogs fall prey to.

You seem to have read about something similar and ran with it without considering what goes into reverse engineering android applications.

As a rule of thumb, if it's embedded in the binary of the application it's really not secure (especially plain strings in the context of NDK)