[ROM] [7.1.2] [grouper] [UNOFFICIAL] LineageOS 14.1 [2021/01/11]
https://forum.xda-developers.com/t/rom-7-1-2-grouper-unofficial-lineageos-14-1-2021-01-11.4112431/

[ROM][NZH54D][2021/01/05][Asus Nexus 7 2012 WiFi/3G][F2FS/EXT4]Android 7.x AOSP
https://forum.xda-developers.com/t/rom-nzh54d-2021-01-05-asus-nexus-7-2012-wifi-3g-f2fs-ext4-android-7-x-aosp.3467514/

この２つが最新セキュリティ更新されてるから　セキュリティアプリ不要