give an identifier to the app_bundle itself

Language Pack did not seem to pick a decent default value for that

Change-Id: I567f24882e16533e10d8ba91b777ad91dc507b87
Reviewed-on: https://gerrit.libreoffice.org/7485
Tested-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>