/usr/share/upstart/sessions/pulseaudio.conf is in ubuntu-touch-session 0.108+16.04.20160407-0ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 | description "Pulseaudio"
author "Ricardo Mendoza <ricmm@ubuntu.com>"
start on started dbus
stop on session-end
respawn
expect daemon
pre-start script
    # Use the Touch specific Pulseaudio script file
    initctl set-env --global PULSE_SCRIPT=/etc/pulse/touch.pa
    initctl set-env --global PULSE_CLIENTCONFIG=/etc/pulse/touch-client.conf
    # Force a default audio role (apps can overwrite this)
    initctl set-env --global PULSE_PROP='media.role=multimedia'
    # Force server-side corking when stalled (playback)
    initctl set-env --global PULSE_PLAYBACK_CORK_STALLED=1
end script
exec pulseaudio --start --log-target=syslog
# Upstart tracks fork() calls, but what Pulse does is fork early
# and then block on a write to a socket. So Upstart thinks that
# it has started while Pulse is still initializing. This stops
# the started event from happening until the dbus-socket is ready
# for people to connect to it.
post-start script
	while true; do
		[ -S /run/user/`id -u`/pulse/dbus-socket ] && break
		sleep 0.1
	done
end script
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