D9089: Suppress unnecessary scroll indicators if the flickable is a ListView with known orientation

[Eike Hein]

hein added a reviewer: garg.

REPOSITORY
  R242 Plasma Framework (Library)

REVISION DETAIL
  https://phabricator.kde.org/D9089

To: hein, #plasma, mart, garg
Cc: plasma-devel, #frameworks, ZrenBot, progwolff, lesliezhai, ali-mohamed, 
jensreuterberg, abetts, sebas, apol, mart