XML Doc Comment incorrectly indents code CDATA section

Version Used: dotnet --version reports: 2.1.200

Steps to Reproduce:

1. dotnet new library to create a new library project
2. Add a DocumentationFile element to the csproj's PropertyGroup element:

<DocumentationFile>bin\$(Configuration)\$(TargetFramework)\$(AssemblyName).xml</DocumentationFile>

3. Add a code example to the triple slash, where the code tag contains a CDATA section

using System;

namespace csdoccomment
{
    /// <summary>This is the Summary</summary>
    /// <example>
    /// <code language="c#">
    /// <![CDATA[
    /// // No Indent
    ///     // four spaces
    ///         /// eight spaces
    /// ]]>
    /// </code>
    /// </example>
    public class Class1
    {
    }
}

4. Compile with dotnet build

Expected Behavior: I would expect the CDATA section to retain the expected level of indention as when authored, relative to the triple slash delimiter ... so the XML file should look as such

<?xml version="1.0"?>
<doc>
    <assembly>
        <name>csdoccomment</name>
    </assembly>
    <members>
        <member name="T:csdoccomment.Class1">
            <summary>This is the Summary</summary>
            <example>
            <code language="c#">
            <![CDATA[
// No Indent
    // four spaces
        /// eight spaces
]]>
            </code>
            </example>
        </member>
    </members>
</doc>

Actual Behavior: However, as you can see, the contents of the CDATA element are indented relative to the indent level of the parent XML tag.

<?xml version="1.0"?>
<doc>
    <assembly>
        <name>csdoccomment</name>
    </assembly>
    <members>
        <member name="T:csdoccomment.Class1">
            <summary>This is the Summary</summary>
            <example>
            <code language="c#">
            <![CDATA[
            // No Indent
                // four spaces
                    /// eight spaces
            ]]>
            </code>
            </example>
        </member>
    </members>
</doc>

The contents of the CDATA section are meant to respect the whitespace ... and in many cases, whitespace can be significant, especially when we're talking about code examples for languages like python or F#.

/cc @dend, @terrajobst