setVisibleXRange conflicts with granularity

I have a dynamic chart and during setup I do:

```
lineChartView.xAxis.granularityEnabled = true
lineChartView.xAxis.granularity = 25
lineChartView.xAxis.forceLabelsEnabled = true
lineChartView.xAxis.labelCount = 20
```

when checking my xAxis label formatter for values, I get the expected 0, 25, 75, 100 etc

When I set my xRange though to:

`lineChartView.setVisibleXRange(minXRange: 25, maxXRange: 500)`

the xAxis label values are incremented by 30

```
0.0
30.0
60.0
90.0
120.0
150.0
180.0
210.0
240.0
270.0
300.0
330.0
360.0
390.0
420.0
450.0
480.0
510.0
540.0
```

EDIT: just a note that as soon as I zoom in a tiny bit, the scale reverts back to the 0, 25, 75 etc.

Start by reproducing the setup with xAxis granularity, forceLabelsEnabled, labelCount, and setVisibleXRange(minXRange:maxXRange:), then inspect those axis and range entry points. Compare labels before and after a slight zoom; done means setting the visible range preserves the configured granularity instead of changing increments until zooming.

Written by the indexing model from the issue text.