Block FRP Writing on SM-T825c

A better solution: https://github.com/shunf4/StopTouchingMyFrp

Description

Some devices like Samsung SM-T825c, does not have the option OEM Unlocking in Development Settings, disabling users to stay rooted while having their Google Account signed in. There are two solutions:

Don't use the stock Google Play Services Core. Use microG instead.
Block FRP status writing by com.android.google.gms after adding Google Accounts at each reboot.

This Magisk module is the latter one. It can:
Execute a script every booting-up. It can re-write the partition named persistent which contains FRP information written by Google Play Service, so that FRP will not automatically turn on.
Tweak framework-res.apk (of SM-T825c firmware T825CZHU1ARA2) to remove com.google.android.gms from config_persistentDataPackageName, preventing Google Play Service from writing FRP partition.

Changelog

2018.06.29 Update : SM-T825c with Magisk enabled runs very slow. I have altered to SuperSU root solution.

v0.0.0.3: change /external_sd/ to /sdcard/ because external SD card won't be mounted to that path

v0.0.0.2: finally made it to work

v0.0.0.1

Requirements

SM-T825c firmware T825CZHU1ARA2
- if the device's firmware is not T825CZHU1ARA2, decompile framework-res.apk , modify the value of config_persistentDataPackageName in framework-res.apk/res/values/strings.xml to an empty string, then re-compile it, replace the resource.arsc & res(directory) of the original framework-res.apk and place it under /sdcard/framework-res/ then reinstall this module. BE CAREFUL OF POSSIBLE BOOTLOOP CAUSED BY INAPPROPRIATE framework-res.apk!
Has /dev/block/bootdevice/by-name/persistent as the persistent partition defined as ro.frp.pst=/dev/block/persistent in /system/build.prop.

Instructions

Install Magisk.
Make sure now your FRP status is not locked (by having not logged in Google Account).
Place framework-res.apk under /sdcard/framework-res/ if you have compiled one for firmwares other than SM-T825c firmware T825CZHU1ARA2.
Install this module.
Enable it and profit. You can now safely log into Google Account.

Links

Module XDA Forum Thread