tdf#127217: Fix buttons in forms not working in Adobe Reader

tdf#127217: Fix buttons in forms not working in Adobe Reader

Regression from 76b5dca9dc0ff60f8f62cbecdee68f8f3b287ceb:
author	Thorsten Behrens <Thorsten.Behrens@CIB.de>	2019-04-09 02:19:14 +0200
committer	Katarina Behrens <Katarina.Behrens@cib.de>	2019-07-03 14:48:45 +0200
commit	76b5dca9dc0ff60f8f62cbecdee68f8f3b287ceb (patch)
tree	e778dad33073a228eb61ab62ce5f38e2a26d07ca
parent	1e8a9c19a6f7b82c9e0c481aee0c04c0780f4433 (diff)
tdf#113448 don't export any font for radio buttons

Don't let only color value in m_aDAString since it'll go here:
        if( !rWidget.m_aDAString.isEmpty() )
        {
            if( !rWidget.m_aDRDict.isEmpty() )
            {
                aLine.append( "/DR<<" );
                aLine.append( rWidget.m_aDRDict );
                aLine.append( ">>\n" );
            }
            else
            {
                aLine.append( "/DR<</Font<<" );
                appendBuildinFontsToDict( aLine );
                aLine.append( ">>>>\n" );
            }
            aLine.append( "/DA" );
            appendLiteralStringEncrypt( rWidget.m_aDAString, rWidget.m_nObject, aLine );
            aLine.append( "\n" );
            if( rWidget.m_nTextStyle & DrawTextFlags::Center )
                aLine.append( "/Q 1\n" );
            else if( rWidget.m_nTextStyle & DrawTextFlags::Right )
                aLine.append( "/Q 2\n" );
        }

But if we shouldn't have /DR at all since we don't want fonts for radiobutton, it also means
we don't want /DA too.
Indeed at the end of 12.7.3.3 https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf:
The default appearance string (DA) contains any graphics state or text state operators needed to establish the
graphics state parameters, such as text size and colour, for displaying the field’s variable text. Only operators
that are allowed within text objects shall occur in this string (see Figure 9). At a minimum, the string shall
include a Tf (text font) operator along with its two operands, font and size. The specified font value shall match
a resource name in the Font entry of the default resource dictionary (referenced from the DR entry of the
interactive form dictionary; see Table 218).

Change-Id: Ib350495d7fc5a7a4fba88d710614a0f67a0b1553
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/111724
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <thorsten.behrens@allotropia.de>