add android_cache group and add phablet user to it

debian/changelog

@@ -1,3 +1,11 @@
+livecd-rootfs (2.223) UNRELEASED; urgency=medium
+
+  * add android_cache group (GID 2001) so that after we switch developer mode
+    to default to the phablet user it is still possible to adb push image
+    tarballs to the /cache partition
+
+ -- Oliver Grawert <ogra@ubuntu.com>  Wed, 16 Jul 2014 14:15:21 +0200
+
 livecd-rootfs (2.222) utopic; urgency=medium
 
   * Precompiling apparmor policies on touch

live-build/ubuntu-touch/hooks/02-add_user_to_groups.chroot

@@ -2,7 +2,7 @@
 
 USER=phablet
 
-DEFGROUPS="tty,sudo,adm,dialout,cdrom,plugdev,audio,dip,video,gps,radio,bluetooth,android_net,android_net2,android_net3,android_graphics,android_input,sdcard_rw,android_media,android_nvram"
+DEFGROUPS="tty,sudo,adm,dialout,cdrom,plugdev,audio,dip,video,gps,radio,bluetooth,android_net,android_net2,android_net3,android_graphics,android_input,sdcard_rw,android_media,android_nvram, android_cache"
 
 /bin/egrep  -i "^audio:" /etc/group
 if [ $? -eq 0 ]; then
@@ -91,6 +91,13 @@ else
 	echo "User android_nvram does not exist in /etc group -- must create"
 	groupadd -g 9997 android_nvram
 fi
+/bin/egrep -i "^android_cache:" /etc/group
+if [ $? -eq 0 ]; then
+	echo "User android_cache exists in /etc/group"
+else
+	echo "User android_cache does not exist in /etc group -- must create"
+	groupadd -g 2001 android_cache
+fi
 
 echo "I: add $USER to ($DEFGROUPS) groups"
 usermod -a -G ${DEFGROUPS} ${USER}