Linear-scaled charts maximum gradient color stop is incorrect and does not match legend

[Lyq322]

Describe the bug
For linear-scaled charts, the maximum gradient color stop is not in the color scheme. It does not match the legend's maximum gradient color stop.

To Reproduce
Steps to reproduce the behavior:

1. Go to any linear-scaled charts, eg linear-scaled vertical bar charts
2. The bug occurs for all color schemes, but is most obvious in the forest color scheme

Expected behavior
For linear-scaled charts, the maximum gradient color stop should be in the color scheme and should match the maximum gradient color stop on the legend.

Screenshots
For example, for the forest color scheme, the second bar's top is yellow but yellow is not in the forest color scheme. From the legend we can see that the maximum gradient color stop is supposed to be orange not yellow.

Demo
n/a

ngx-charts version
20.4.1

Additional context
n/a