Leading semicolon line-bolding made visible in printable version

When bolding a line using ";" at the start, the text in &printable=yes shows
the line without bolding, even though text in the printable version does appear
formatted when using ''' for bolding and '' for italics.

Bug: 49752
Change-Id: I84545fe9c9240293818c1f6f938fc3bba7c2aa06
Merge "Leading semicolon line-bolding made visible in printable version"