`homescreen` relies on `/etc/default/homescreen` to contain its
environment variables, however this feature was lost when we switched
to systemd services.
This commit restores this feature by instructing systemd to source
`/etc/default/homescreen` if it exists.
Bug-AGL: SPEC-4161
Signed-off-by: Arnaud Ferraris <arnaud.ferraris@collabora.com>
Change-Id: I62c8597eac7d14d9d5166f9c559a1538398cd0c8
[Service]
Type=simple
+EnvironmentFile=-/etc/default/homescreen
ExecStart=/usr/bin/homescreen
Restart=on-failure