init: fix return value for android uid/gid check

Now get_android_id function returns -EINVAL if the uid/gid is not in the list
of android ids. This will allow ueventd to catch invalid ids and report the
error.

Change-Id: I943b04dd64d518891623e1ee2d561b8061af4863
Signed-off-by: Veeren Mandalia <v.mandalia@sta.samsung.com>