[API] removed Google collect library

Only the BiMap was used from this library and this only in one place.

Changed the affected class to use two hash maps instead of a bi map.

Change-Id: I88bc43ddc4ad2a83fd8dea801f6758d39bbc7903
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1141
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>