signalfx_single_value_chart missing support for max and min values when secondary_visualization is Radial or Linear

[RomeroGaliza]

When trying to create a signalfx_single_value_chart with the following attributes:

resource "signalfx_single_value_chart" "generic_gauge_chart" {

  name         = var.chart_name
  description  = var.chart_description
  program_text = var.chart_program_text

  unit_prefix      = "Metric"
  color_by         = "Scale"
  refresh_interval = 1

  secondary_visualization = "Radial"

  color_scale {
    color = "green"
    lt    = 10
  }

  color_scale {
    color = "yellow"
    gte   = 10
    lte   = 60
  }

  color_scale {
    color = "red"
    gt    = 60
  }

}

I get the following error:

Error: Unexpected status code: 400: {
  "code" : 400,
  "message" : "Open ended range not allowed"
}

  on main.tf line 1, in resource "signalfx_single_value_chart" "generic_gauge_chart":
   1: resource "signalfx_single_value_chart" "generic_gauge_chart" {

I noticed this case is not covered by your test (https://github.com/splunk-terraform/terraform-provider-signalfx/blob/c6041ba5f36e51f22b68b63c96650a91d06a9f5c/signalfx/resource_signalfx_single_value_chart_test.go) in version 6.7.3.