Summary:
This prevents issues with buttons jumping around when canPlay/canPause is false, as some mpris players do not report consistent values.

Additionally, gives the play/pause button a bit more attention when enabled. What do you think?

When playing/pausing is enabled (i.e. nearly always):
{F5728047}

When disabled:
{F5728048}

Reviewers: #kde_connect, #vdg, albertvaka

Reviewed By: #kde_connect, albertvaka

Subscribers: albertvaka, nicolasfella

Differential Revision: https://phabricator.kde.org/D10796