🍒 lookandfeel: Explicitly set theme to Breeze in defaults

Original commit message(s)

• lookandfeel: Explicitly set theme to Breeze in defaults

Currently, we only set "library" to "org.kde.breeze", which means for "theme" the fallback mechanism is used. Depending on how plasma-workspace was compiled, this is either Breeze or kwin4_decoration_qml_plastik.

When plasma-workspace was built without Breeze, we end up with library=org.kde.breeze, theme=kwin4_decoration_qml_plastik, which is not a valid combination. While this will ultimately result in Breeze decoration being used as intended, it breaks the decoration KCM highlight since it tries to select a combination of library/theme that doesn't exist. KWin might also get confused, its support information also prints this bogus configuration.

While this doesn't fix the underlying issue of defaults handling in lnf (see also !3345) and might also indicate a packaging issue of plasma-workspace, it is imho still advisable to be explicit.

Signed-off-by: Sebastian Stark sebastian.stark@advantest.com (cherry picked from commit c520c441)

Reason for the change

Cherry pick of !4748 (merged)