ubuntu-touch/hooks: add phablet user's group membership statically

Well, even though the phablet user is in extrausers db, the group it
needs to be in is still in /etc/group. Currently, we don't have a better
way. The alternative which is utilizing glibc's [SUCCESS=merge]
directive would require us patching libnss-extrausers which has been
orphaned for quite some time now.

Ubuntu Core based on snap also has the same problem.

https://forum.snapcraft.io/t/adding-users-to-system-groups-on-ubuntu-core/20109
canonical/core20#72

Author: peat-psuwit

live-build/ubuntu-touch/hooks/00-uid-gid-fix.chroot_early

@@ -125,8 +125,8 @@ root:x:0:
 daemon:x:1:
 bin:x:2:
 sys:x:3:
-adm:x:4:syslog
-tty:x:5:
+adm:x:4:syslog,phablet
+tty:x:5:phablet
 disk:x:6:
 lp:x:7:
 mail:x:8:
@@ -135,15 +135,15 @@ uucp:x:10:
 man:x:12:
 proxy:x:13:
 kmem:x:15:
-dialout:x:20:
+dialout:x:20:phablet
 fax:x:21:
 voice:x:22:
-cdrom:x:24:
+cdrom:x:24:phablet
 floppy:x:25:
 tape:x:26:
-sudo:x:27:
-audio:x:1005:
-dip:x:30:
+sudo:x:27:phablet
+audio:x:1005:phablet
+dip:x:30:phablet
 www-data:x:33:
 backup:x:34:
 operator:x:37:
@@ -153,9 +153,9 @@ src:x:40:
 gnats:x:41:
 shadow:x:42:
 utmp:x:43:
-video:x:44:
+video:x:44:phablet
 sasl:x:45:
-plugdev:x:46:
+plugdev:x:46:phablet
 staff:x:50:
 games:x:60:
 users:x:100:
@@ -172,22 +172,22 @@ rtkit:x:109:
 whoopsie:x:110:
 lightdm:x:111:
 nopasswdlogin:x:112:
-bluetooth:x:1002:
+bluetooth:x:1002:phablet
 lxc-dnsmasq:x:114:
 pulse:x:115:
 pulse-access:x:116:
 system:x:1000:
-radio:x:1001:
-gps:x:1021:
-android_net:x:3003:
-android_net2:x:3004:
-android_net3:x:3002:
-android_graphics:x:1003:
-android_input:x:1004:
-sdcard_rw:x:1015:
-android_media:x:1013:
-android_nvram:x:9997:
-android_cache:x:2001:
+radio:x:1001:phablet
+gps:x:1021:phablet
+android_net:x:3003:phablet
+android_net2:x:3004:phablet
+android_net3:x:3002:phablet
+android_graphics:x:1003:phablet
+android_input:x:1004:phablet
+sdcard_rw:x:1015:phablet
+android_media:x:1013:phablet
+android_nvram:x:9997:phablet
+android_cache:x:2001:phablet
 systemd-timesync:x:113:
 systemd-network:x:117:
 systemd-resolve:x:118:
@@ -212,8 +212,8 @@ root:*::
 daemon:*::
 bin:*::
 sys:*::
-adm:*::syslog
-tty:*::
+adm:*::syslog,phablet
+tty:*::phablet
 disk:*::
 lp:*::
 mail:*::
@@ -222,15 +222,15 @@ uucp:*::
 man:*::
 proxy:*::
 kmem:*::
-dialout:*::
+dialout:*::phablet
 fax:*::
 voice:*::
-cdrom:*::
+cdrom:*::phablet
 floppy:*::
 tape:*::
-sudo:*::
-audio:*::pulse
-dip:*::
+sudo:*::phablet
+audio:*::pulse,phablet
+dip:*::phablet
 www-data:*::
 backup:*::
 operator:*::
@@ -240,9 +240,9 @@ src:*::
 gnats:*::
 shadow:*::
 utmp:*::
-video:*::
+video:*::phablet
 sasl:*::
-plugdev:*::
+plugdev:*::phablet
 staff:*::
 games:*::
 users:*::
@@ -259,22 +259,22 @@ rtkit:!::
 whoopsie:!::
 lightdm:!::
 nopasswdlogin:!::
-bluetooth:!::
+bluetooth:!::phablet
 lxc-dnsmasq:!::
 pulse:!::
 pulse-access:!::
 system:!::
-radio:!::
-gps:!::
-android_net:!::
-android_net2:!::
-android_net3:!::
-android_graphics:!::
-android_input:!::
-sdcard_rw:!::
-android_media:!::
-android_nvram:!::
-android_cache:!::
+radio:!::phablet
+gps:!::phablet
+android_net:!::phablet
+android_net2:!::phablet
+android_net3:!::phablet
+android_graphics:!::phablet
+android_input:!::phablet
+sdcard_rw:!::phablet
+android_media:!::phablet
+android_nvram:!::phablet
+android_cache:!::phablet
 systemd-timesync:!::
 systemd-network:!::
 systemd-resolve:!::