LeAudioTestApp: Use primitive int.class as matching parameter for int

Integer parameter is not valid for primitive int. Method parameters
missmatch Integer vs int may missmatch for class method reflection.

Tag: #feature
Test: Use add/remove node to/from group
Sponsor: jpawlowski@
Bug: 150670922
Bug: 230340466
Change-Id: I08a4057e9a6fc9fa36194082428f7c58d292dc96
(cherry picked from commit c332e46d7602457a5a4408cc8e79af6d6ef42e31)