Regression in 4.12.0: SetupAllProperties resets indexer setups

[stakx]

Code to reproduce:

public interface IX
{
    string this[int index] { get; }
}

[Fact]
void SetupAllProperties_should_not_reset_indexer_setups()
{
    var mock = new Mock<IX>();
    mock.SetupGet(x => x[1]).Returns("value from setup");
    Assert.Equal("value from setup", mock.Object[1]);  // passes
    mock.SetupAllProperties();
    Assert.Equal("value from setup", mock.Object[1]);  // fails
}

This is caused by this line:

https://github.com/moq/moq4/blob/81d1fb24b5a9c5ceb443114b1657137501c4f9e5/src/Moq/SetupCollection.cs#L62

The filter condition should be more specific and rule out indexer accessors.