[FR] add OS/Apps key signing setup

[steadfasterX]

Description

describe your feature request as detailed as possible:

Include/move: https://github.com/sfX-android/android_buildtools/tree/main/sign

Target version

What's your current custom OS and Android version you're building for:

...

_What Android version should support that feature (add an x within the [ ] brackets, select all that should

• [x] Android 9
• [x] Android 10
• [x] Android 11
• [x] Android 12
• [x] Android 13
• [x] Android 14

What custom OS should support that feature (add an x within the [ ] brackets, select / add all that should apply):

• [x] Lineage OS
• [x] AXP.OS
• [x] AOSP

Note

when sharing logs it is strongly recommended using github gists