On Android 4.2.2, this setting applies globally. Remember to disable it after installing if you prefer.
Here is a comprehensive guide on how to find, install, and optimize Firefox for Android 4.2.2. The Compatibility Reality Firefox Apk Android 4.2.2
The for your specific CPU (ARMv7 vs x86) Lightweight alternatives like Opera Mini or Via Browser Steps to fix SSL certificate errors on old Android versions Which of these would help you get that device back online? Will Firefox work on my mobile device? - Mozilla Support Firefox is compatible with Android 8.0 or above devices. Mozilla Support On Android 4