ArrayData::try_new cannot always return expected error.

[HaoYang670]

Find the bug when working on #911.

To Reproduce
Steps to reproduce the behavior:
Just do a small change on https://github.com/apache/arrow-rs/blob/master/arrow/src/array/data.rs#L1734-L1750
Set null_count to be None instead of Some(0)

    #[test]
    #[should_panic(expected = "null_bit_buffer size too small. got 1 needed 2")]
    fn test_bitmap_too_small() {
        let buffer = make_i32_buffer(9);
        let null_bit_buffer = Buffer::from(vec![0b11111111]);

        ArrayData::try_new(
            DataType::Int32,
            9,
            None,
            Some(null_bit_buffer),
            0,
            vec![buffer],
            vec![],
        )
        .unwrap();
    }

This test will panic at "range end index 2 out of range for slice of length 1".

Expected behavior
Panic at null_bit_buffer size too small. got 1 needed 2