`PathMarkupParser` crashes with `InvalidDataException`: 'Invalid bool rule.'

Describe the bug PathMarkupParser crashing

To Reproduce Steps to reproduce the behavior:

In a new project, use the following XAML:

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="AvaloniaApplication1.MainWindow"
        Title="AvaloniaApplication1">
  <Button>
    <PathIcon Data="M17.432 11.619c.024.082.04.165.04.247V26.54c0 .37-.271.552-.605.409l-5.339-2.282c-.336-.144-.604-.558-.604-.926V9.066c0-.368.27-.551.604-.409l5.339 2.283a.898.898 0 01.27.188c.09.169.189.333.295.49M9.615 9.07v14.675c0 .368-.27.782-.605.925l-5.339 2.282c-.334.143-.604-.04-.604-.408V11.868c0-.368.269-.782.604-.926l5.34-2.282c.333-.143.604.04.604.41m15.713 4.173V23.74c0 .368-.27.782-.605.926l-5.338 2.282c-.334.143-.604-.04-.604-.41V13.216c1.015 1.231 2.702 3.615 3.136 6.3h.312c.43-2.665 2.087-5.033 3.099-6.272m-3.217-2.39c-2.065 0-3.738-1.705-3.738-3.808 0-2.102 1.673-3.807 3.738-3.807 2.064 0 3.738 1.705 3.738 3.807 0 2.103-1.674 3.808-3.738 3.808M22.054 2c-2.768 0-5.012 2.286-5.012 5.105 0 1.378.531 2.693 1.401 3.611 0 0 2.928 2.912 3.488 6.389h.279c.56-3.477 3.471-6.389 3.471-6.389.873-.918 1.386-2.232 1.386-3.61 0-2.82-2.245-5.106-5.013-5.106"
      VerticalAlignment="Center" />
  </Button>
</Window>

Expected behavior

Icon similar to:

Desktop (please complete the following information):

• OS: [e.g. Windows, Mac, Linux (State distribution)]
• Version [e.g. 0.10.0-rc1 or 0.9.12]

Additional context

Frameworks like UWP and WPF handles this correctly.

[Gillibald]

Y it looks like flags are more strict flag::=("0"|"1")

[Gillibald]

Will have a look shortly.