[Metric] SparkLine - chart not rendered when the trend is empty

[alexwizp]

Regression of #2411

When the metric chart is visualized with an empty trend, the chart component fails to render, and the following error message appears in the console:

How to reproduce:

1. Configure any Metric chart
2. Pass [] as value for trend attribute.

Possible solution:

1. Apply the following fix. This diff represents the change in line 56 of the sparkline.tsx file.

- if (!trend) {
+ if (!trend?.length) {

Screen:

Trend was set to []