fix alienarena icon
fix alienarena icon

Summary:
- reverse gradient
- change objects
- clear code
- add shadow
- pixel align
Compare:
{F2163381}
SVG:
{F2163382}

Reviewers: andreask, #breeze, andreaska

Reviewed By: #breeze, andreaska

Subscribers: alex-l, #frameworks

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D4259

KDE/breeze-icons,KDE/breeze-icons,KDE/breeze-icons,KDE/breeze-icons,KDE/breeze-icons