Redundant systemd instance makes WAM and homescreen crash

[update: see comment comment-20920]

When I start a halibut/master image with agl-html5-framework, I can see the homescreen crash after some seconds.

I can see two crashes:

{{$ coredumpctl }}
TIME PID UID GID SIG COREFILE EXE
Sat 2019-06-29 08:29:46 UTC 1120 0 0 5 present /usr/bin/WebAppMgr
Sat 2019-06-29 08:30:22 UTC 1280 0 0 6 present /var/local/lib/afm/applications/homescreen/0.1/bin/HomeScreen

This is the sequence of events in the log:

Jun 29 08:29:46 intel-corei7-64 systemd-coredump[1187]: Process 1120 (WebAppMgr) of user 0 dumped core.
Jun 29 08:30:18 intel-corei7-64 systemd[1119]: WebAppMgr.service: Service RestartSec=50s expired, scheduling restart.
Jun 29 08:30:18 intel-corei7-64 systemd[1119]: WebAppMgr.service: Scheduled restart job, restart counter is at 1.
Jun 29 08:30:18 intel-corei7-64 systemd[1119]: Stopped "WebAppMgr is responsible for running web apps and manage their lifecycle".
Jun 29 08:30:18 intel-corei7-64 systemd[1119]: Started "WebAppMgr is responsible for running web apps and manage their lifecycle".
Jun 29 08:30:18 intel-corei7-64 WebAppMgr[1408]: ## (DEBUG)[int main(int, const char**)] ### Starting /usr/bin/WebAppMgr
Jun 29 08:30:18 intel-corei7-64 WebAppMgr[1408]: ## (DEBUG)[virtual int WebRuntimeAGL::run(int, const char**)] WebRuntimeAGL::run
Jun 29 08:30:18 intel-corei7-64 WebAppMgr[1408]: ## (DEBUG)[virtual int WebRuntimeAGL::run(int, const char**)] WebRuntimeAGL - creating SharedBrowserProcessRuntime
Jun 29 08:30:18 intel-corei7-64 WebAppMgr[1408]: ## (DEBUG)[int WamSocketLockFile::openLockFile()] Failed to open lock file descriptor
Jun 29 08:30:18 intel-corei7-64 WebAppMgr[1408]: ## (DEBUG)[bool WamSocketLockFile::createAndLock()] Failed to lock file -1
Jun 29 08:30:18 intel-corei7-64 WebAppMgr[1408]: ## (DEBUG)[virtual int SharedBrowserProcessRuntime::run(int, const char**)] Trying to start shared browser process but process is already running
Jun 29 08:30:18 intel-corei7-64 systemd[1119]: WebAppMgr.service: Main process exited, code=exited, status=255/n/a
Jun 29 08:30:18 intel-corei7-64 systemd[1119]: WebAppMgr.service: Failed with result 'exit-code'.
Jun 29 08:30:22 intel-corei7-64 systemd-coredump[1363]: Process 1280 (HomeScreen) of user 0 dumped core.

Reproduced in Minnowboard, but likely to affect other platforms