Build: Switch to Magisk as the built in root [2/2] ยท AICP/build@2b25066

Pretty much identical to https://github.com/DirtyUnicorns/android_build/commit/2871a7b10b1ae6b6bdda049e33421ab37057f4d1 Modified and updated for TWRP 3.0.3-x by @nathanchance Change-Id: Ic0cc0b6e...