Include directivity configuration text file in self_test.prm to increase coverage

(Generic issue template)

With the addition of Contribution 38 philips/contribution-38-control-metadata-reverb in MR !724 (merged), both test cases using the directivity configuration in self_test.prm call the binary configuration file from the text configuration file. To increase the coverage, one proposal is to remove the link to binary file for one of the test cases.