device-samsung-klte: add android adaptation to device package

Lots of device-specific configurations:

• Android mount points and mounts
• Android udev rules for platform devices (needed for android services to run)
• NetworkManager device-specific config
• wpa_supplicant device-specific config
• extra helper scripts to set backlight brightness, get battery status
• use kernel cmdline from downstream android to keep it as close to android as possible. Important for android in lxc container later

WIP stuff:

• add nonfree-userland subpackage, that pulls hybris adaptation
• add -hybris subpackage, installed only if nonfree-userland was chosen manually
• add -hybris-x11 subpackage, installed only if -hybris and xorg-server
• deferred_initcalls to postmarketos-base !338 (merged)
• 60-persistent-v4l.rules to /dev/null
• remove 60-persistent-v4l.rules from lxc-android !391 (merged)
• fix android group names in udev rules
• clean up fstab
• clean up add-android-groups and add it with logcat to lxc-android, add hybris-base !351 (merged)
• unlock-plasma to postmarketos-ui-plasma-mobile !337 (merged)