tmf.xml: Move the ImmutableMap of action in the constructor

tmf.xml: Move the ImmutableMap of action in the constructor

This patch moves the ImmutableMap of action in the constructor in the
event handler.
This change prevents a copy of the maps of test and action each time
they are needed. The maps are build in the constructor and are
unmodifiable.

Change-Id: I5772528f50fde545a63215beb918d2f7f9a88005
Signed-off-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/78187
Reviewed-by: Hudson CI
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>