Cors Filter does an add to the HeaderMap instead of set

[SaumyaSoman]

Describe the bug
Cors Filter does an add to the HeaderMap in setOriginAndCredentials and addExposedHeaders methods . This will add a header without replace existing headers.

To Reproduce
Create a non preflight request with origin and expose headers and add cors filter to it. Call the API couple of times. Headers keep increasing.

Expected behavior
A set should be done instead of add