Currently, when any call is terminated, audio profile/routing is
switched to the default one.
This is a problem when already into a call and getting a second one:
rejecting the new call will keep the first one going, but with the wrong
audio profile, making it difficult (or, on the PinePhone, impossible) to
keep talking.
This patch makes sure there is no other ongoing call before switching
the audio mode, so that it's possible to keep the first call going even
after rejecting the second one.
`callaudiod` is a device-agnostic service for routing audio during voice
calls, called through `libcallaudio`.
It allows us to automatically switch profiles when entering a call,
enable the speaker output or mute the microphone, and can therefore be
used to replace the current Librem 5-specific hacks.
For some locales, the buttons' labels can be quite long, making the
window wider than the display.
Using a line wrap will solve this issue when there wouldn't be shorter
translation alternatives. This requires reducing the encryption indicator's
margins so the window height doesn't grow beyond the available display size.