Extend MauiMaterialButton to expose a constructor which accepts a style id override

[EquinoX28]

Description

I would like to have the possibility to create a MauiMaterialButton with a custom android style.
The current implementation extends MaterialButton and is exposing a constructor that accepts the android context only.

public MauiMaterialButton(Context context) : base(context) { }

Materialbutton also has a constructor accepting a style override (defStyleAttr).

public unsafe MaterialButton(Context context, IAttributeSet? attrs, int defStyleAttr) : base(IntPtr.Zero, JniHandleOwnership.DoNotTransfer) {...}

Without exposing this constructor it seems like there's no simple way to extend MauiMaterialButton to benefit from automatic image icon scaling and still define a custom (or variable) android style.

Public API Changes

public MauiMaterialButton(Context context, IAttributeSet? attrs, int defStyleAttr) : base(Context context, IAttributeSet? attrs, int defStyleAttr) { }

Intended Use-Case

I have a situation where I select an android style in a derived button handler based on a buttonType enum property.

private static int GetStyle(BindableObject element)
{
    int style = Resource.Attribute.materialButtonStyle;

    if (element is CustomButton btn)
    {
        var btnType = btn.ButtonType;
        switch (btnType)
        {
            case CustomButtonType.Contained:
                break;

            case CustomButtonType.Outlined:
                style = Resource.Attribute.materialOutlinedButtonStyle;
                break;

           ...

            case CustomButtonType.Text:
                style = Resource.Attribute.materialTextButtonStyle;
                break;
        }
    }
    return style;
}

For this I need to override CreatePlatformView and create a new Materialbutton with the android style that corresponds to the buttonType enum. I can't use the MauiMaterialButton for this yet, as it does not expose the necessary constructor.

var button = new MaterialButton(Context, null, GetStyle((BindableObject)VirtualView))

The android styles are based on the Widget.MaterialComponents.Button styles, e.g. TextButton and OutlinedButton.

[rmarinho]

Fixed by #22455