Fixing the description for bluetooth audio test
checkbox-touch: fix crashing when saving report on desktop

This patch makes Checkbox Touch use correct (expanded) path to Documents
directory when saving report.
"automatic merge of lp:~cypressyew/checkbox/bt-audio-desc-fix/ by tarmac [r=zkrynicki][bug=1391747][author=cypressyew]"
"automatic merge of lp:~kissiel/checkbox/fix-export-path/ by tarmac [r=zkrynicki][bug=][author=kissiel]"