Incoming call appearing behind lockscreen

Reproduction

1. Lock screen
2. Call inbound
3. Hear ringtone
4. Unlock to answer

librem-5-chestnut-inbound-call-audio-but-behind-lockscreen-2020-01-30

Possibly related to: #41 (closed)

purism@l5b:~$ uname -a
Linux l5b 5.3.0-librem5-h1 #1 SMP PREEMPT Sat Jan 25 09:55:23 CET 2020 aarch64 GNU/Linux
purism@l5b:~$ dpkg -s phosh | grep Version
Version: 0.1.7
purism@l5b:~$ dpkg -s phoc | grep Version
Version: 0.1.5pureos1
purism@l5b:~$ dpkg -s calls | grep Version
Version: 0.1.2
purism@l5b:~$