If nothing works:
Use this guide only as a short-term solution while you back up your data and consider upgrading to a custom ROM (e.g., LineageOS 14.1 or 15.1, which bring Android 7.1/8.1 to KitKat-era hardware). Alternatively, retire the device for basic offline tasks (MP3 player, e-reader, dedicated GPS).
: Another reliable alternative for finding historical versions of system apps. How to Install the APK on Your Device