forms: replace StringBuffer with StringBuilder

Change-Id: Iee1b7ea214e5ed2fdd8bd5fe93dc16fbaaf312a8
Reviewed-on: https://gerrit.libreoffice.org/11720
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
forms: use Arrays.toString in integration.forms.RadioButtons

Change-Id: I797692857c874d879192ca9a4ff73b98ed5ebd86
Reviewed-on: https://gerrit.libreoffice.org/11721
Reviewed-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>
Tested-by: Samuel Mehrbrodt <s.mehrbrodt@gmail.com>