raar-record-handler: Increase minimum recording size

Increase the minimum recording file size from 1 to 20 MiB. This should
prevent sporadic, premature recording movements, especially on busy
systems in combination with the default FLAC codec (which produces
files that grow between 0.05 and 0.14 MiB/s).

The size of 20 MiB shouldn't be too small for lossless files (FLAC and
WAV) but also not too high for lossy codecs such as MP3 with 96 Kbit/s

bin/raar-record-handler.sh

@@ -69,7 +69,7 @@ echo "Watching for new records in ${watchDir}"
 echo "Recordings will be moved to ${destDir}"
 
 # The minimum size a recording must have to trigger an archival
-minFileSize="1048576" # 1 MiB
+minFileSize="$(( 20 * 1048576 ))" # 20 MiB
 
 inotifywait --monitor --event close_write "${watchDir}" | while read \
     watchedFileName eventNames eventFileName