[REFACTOR] Removes Syso from ActivityHandler

Change-Id: If848d4a9e21a5318bb22a4d2d69c995786c30cd8
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1965
Tested-by: Jenkins CI
Reviewed-by: Holger Schmeisky <google@schmeisky.com>