kmsaudiomixer: Set latency property to audiomixer
kmsaudiomixer: Set latency property to audiomixer

Change-Id: I5f812805e8f3f01594f369a05b0ece52b6b674ff

ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core,ESTOS/kms-core,ESTOS/kms-core