Fixed single bit RLE test files

[CPBridge]

Fixing the single bit RLE test files in line with the revised understanding of single bit RLE discussed in this comment.

I will create a corresponding PR on pydicom soon.

Describe the changes

The related issue or a description of the bug or feature that this PR addresses.

Tasks

• In a branch on your fork of pydicom-data, add or modify data files
• Create a pull request for pydicom-data
• Update the commit hash for the urls in a fork/branch of the pydicom file [urls.json]https://github.com/pydicom/pydicom/blob/master/pydicom/data/urls.json and create a pydicom pull request
• pydicom unit tests passing
• Documentation updated (if needed)

[CPBridge]

@scaramallion