[ubports/focal] ButtonStyle.qml: use theme base colour
Backport: !66 (merged)
This fixes some small inconsistencies (such as in the Settings app, in the updates page, between the "Open" buttons and the "Stop" button when searching for updates).
Backport: !66 (merged)
This fixes some small inconsistencies (such as in the Settings app, in the updates page, between the "Open" buttons and the "Stop" button when searching for updates).