settings-dialog: Add a way to modify chatty autostart

Fixes #501
7 jobs for wip/sadiq/configurable-autostart in 8 minutes and 53 seconds
latest
Status Job ID Name Coverage
  Build
passed #360881
librem5
build-pureos-gcc-byzantium

00:01:40

 
  Test
passed #360883
librem5
check-po

00:00:17

passed #360882
librem5
test:debian-gcc

00:01:37

23.0%
 
  Package
passed #360884
librem5
package-pureos-byzantium

00:01:47

passed #360885
librem5:arm64
package-pureos-byzantium:arm64

00:05:34

 
  Test Package
passed #360886
librem5
autopkgtest-pureos-byzantium-package

00:01:13

passed #360887
librem5
lintian-pureos-byzantium-package

00:00:43