CreatePrimaryIndexAsync throws exceptions / ignores IgnoreIfExists

Summary: using the CreatePrimaryIndexAsync throws exception when a primary index already exists, no matter what IgnoreIfExists is set to.

Repro:

1. Use CreatePrimaryIndexAsync to create an index.
2. Use CreatePrimaryIndexAsync to create an index again (with or without IgnoreIfExists set to true or false)
3. (see attached source code for complete example)

Expected:

If IgnoreIfExists set to true, I would expect no exception if the index already exists.

Actual:

Exception (see attached)

Notes:

Looking at the code, it appears that IgnoreIfExistsValue in CreatePrimaryQueryIndexOptions is never actually used. The ignore flag is ignored!