audiomixer: Adapt test to use the new defined macro MANUAL_CHECK
audiomixer: Adapt test to use the new defined macro MANUAL_CHECK

Change-Id: Iaf564cd2deacb08b86fc1227f7fa20c5b6a56ece

shelsonjava/kms-core,Kurento/kms-core,Kurento/kms-core,KurentoLegacy/gst-kurento-plugins,TribeMedia/kms-core,shelsonjava/kms-core,KurentoLegacy/gst-kurento-plugins,ESTOS/kms-core,Kurento/kms-core,Kurento/kms-core,KurentoLegacy/gst-kurento-plugins,TribeMedia/kms-core,ESTOS/kms-core,ESTOS/kms-core,TribeMedia/kms-core,shelsonjava/kms-core,KurentoLegacy/gst-kurento-plugins,TribeMedia/kms-core,shelsonjava/kms-core,ESTOS/kms-core