I would like to set the Keyboard Type the same way as it's possible for the regular Entry (see docs).
The reason is that I have a MaskedEntry with a mask that allows only numeric input. That's why I want to set Keyboard="Numeric".
This is how it should look like in the end:
<telerik:RadTextMaskedEntry x:Name="entry" Keyboard="Numeric" Mask="00:00" />