Formatter doesn't increase ident in multiline list patterns correctly

[DoctorKrolic]

Found while working on a compiler PR (link)

Version Used:
VS 17.10.0 Preview 5.0

Steps to Reproduce:
Run formatter on this code:

MyClass[] arr = [new()];

if (arr is
    [
    {
        Prop: 1,
        AnotherProp: 2
    }
    ])
{

}

class MyClass
{
    public int Prop { get; set; }

    public int AnotherProp { get; set; }
}

Expected Behavior:

MyClass[] arr = [new()];

if (arr is
    [
        {
            Prop: 1,
            AnotherProp: 2
        }
    ])
{

}

class MyClass
{
    public int Prop { get; set; }

    public int AnotherProp { get; set; }
}

Actual Behavior:
Quite the opposite - when I run formatting on correct code, it dedents it back:

[RikkiGibson]

I suspect the same issue may be occurring here, even though there is no collection-expr involved.

Before:

if (sym switch
    {
        MethodSymbol method => (Symbol)method.PartialImplementationPart,
        SourcePropertySymbol property => property.PartialImplementationPart,
        _ => throw ExceptionUtilities.UnexpectedValue(sym)
    }
    is { } implementation)
{

After:

if (sym switch
{
    MethodSymbol method => (Symbol)method.PartialImplementationPart,
    SourcePropertySymbol property => property.PartialImplementationPart,
    _ => throw ExceptionUtilities.UnexpectedValue(sym)
}
    is { } implementation)
{

Expected: no formatting warning is reported for the "Before" case.