vega label attributes like color and angle are not working

[ThiloSchoenfelder]

Kibana version:
V6.7.0

Elasticsearch version:
V6.7.0

Describe the bug:
when I set the color and angle for a axes label in vega is works fine in the Vega Editor, but it did not shows any changes in Kibana

"axes": [
{"orient": "bottom", "scale": "x",
"labelAngle": -45,
"labelColor": "lightgray",
"labelPadding": 20
}

The labels are still on 0 degrees and black.

related to the dark theme bug #16456

[elasticmachine]

Pinging @elastic/kibana-app

[flash1293]

Kibana currently uses vega 4.3 and vega-lite 2.6 . It seems like these properties got added in later versions and are not supported.

Vega editor marks the field as "not allowed" if the spec version is set to 2.6 in the schema: https://vega.github.io/editor/#/url/vega-lite/N4KABGBEAkDODGALApgWwIaQFxUQFzwAdYsB6UgN2QHN0A6agSz0QFcAjOxge1IRQyUa6ALQAbZskoAmOgDY6ABjoArWNwB2kADTgoAE3R5MOYJFYAnMdgNH0fZEbxjkIgO6OWyC3XiwKkAC+uhCQGBYA1jaQ7OgWOnqQyBrw3PqMGtQ2oBChAB7ZerlQeIyoyACqGszRqJosCcWhAGaMyGL60YZ4yI1NkHgAnoS9OJDcFuka6NYh-eh5jLDZA8wu0QCy9Yhg3M1gXmCDjvHaUGLo7O0AwtxiE9EWyJ2BRWDBb5CDhU1Q6NTUJ60HrRVKsDR4PrFAbDUZQACOrHQEOYRkYVEgbw+0NS93ipjeLTaHWiHiMKFOhJKsOiGm4qAyMyhuUgCBmcJyvwM9PQGRsAG1WeCdJBmtwstpIPoLIwAF6y9aSiy8rSS2B0tyQAC6c1+kGVmThgoAxMgAOyxACs0hFxvgZvt9tt6GQ9uQAA5bQBGZpmi0AFltAE5-XILZ0tVTsf0XNRkp1TKtnHDIAB1TwUg4017FHPvECvIA

There is already an issue (#31413) for that, but it's currently blocked by our webpack build process.

[timroes]

Closing this in favor of the update to Vega 5 issue (#31413).