[Bug] Gif not animated on iOS when using different DefaultThreadCurrentCulture

[e1T]

Setting the CultureInfo.DefaultThreadCurrentCulture to some different values than 'en-US' can result in .gif images not animating on iOS. On Android the gif is animating correctly as expected.

Not working correctly:

CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("nl-NL");
CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("de-DE");
CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("es-ES");

I have tried a few different values, and these seem to work correctly however:

CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("en-US");
CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("fr-FR");
CultureInfo.DefaultThreadCurrentCulture = new CultureInfo("ru-RU");

Steps to reproduce:

1. Generate a sample app (e.g. TipCalc)
2. In TipCalc.Core/App.cs add the line defining the DefaultThreadCurrentCulture
3. Add an animated gif to the view, e.g. <Image Source="office.gif" IsAnimationPlaying="True" />

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EDIT:
It seems to be caused by the ImageAnimationHelper in Xamarin.Forms.Platform.iOS on line 54:

double.TryParse(unclampedDelayTimeValue.ToString(), out delayTime);

In the Xamarin.Forms Control Gallery this results in a value of 0.33 to be parsed as 33.

The solution which seems to fix the issue is to ignore the thread culture, e.g.:

double.TryParse(unclampedDelayTimeValue.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture, out delayTime);

The same probably applies to line 56.