SDC-8191. Upgrade Kinesis producer library to 0.12.8
SDC-8191. Upgrade Kinesis producer library to 0.12.8

Updating kpl.version 0.12.6->0.12.8

Change-Id: I1fbb0c6f0211f90aa59fe549ed647d886e24f885
Reviewed-on: https://review.streamsets.net/12317
Tested-by: StreamSets CI <809627f37325a679986bd660c7713476a56d59cd@streamsets.com>
Reviewed-by: Adam Kunicki <0e18f44c1fec03ec4083422cb58ba6a09ac4fb2a@streamsets.com>

kunickiaj/datacollector,kunickiaj/datacollector,SandishKumarHN/datacollector,rockmkd/datacollector,kunickiaj/datacollector,SandishKumarHN/datacollector,rockmkd/datacollector,kunickiaj/datacollector,streamsets/datacollector,rockmkd/datacollector,streamsets/datacollector,rockmkd/datacollector,SandishKumarHN/datacollector,SandishKumarHN/datacollector,SandishKumarHN/datacollector,streamsets/datacollector,streamsets/datacollector,kunickiaj/datacollector,rockmkd/datacollector,streamsets/datacollector