L2SS-393: Use alias in lofar20rc.sh to install githooks

bin/update_submodules.sh

+#!/bin/bash
+git submodule update --init

bootstrap/etc/lofar20rc.sh

@@ -12,6 +12,10 @@
 ABSOLUTE_PATH=$(realpath $(dirname ${BASH_SOURCE}))
 export LOFAR20_DIR=${1:-$(realpath ${ABSOLUTE_PATH}/../..)}
 
+if [ ! -f "${LOFAR20_DIR}/.git/hooks/post-checkout" ]; then
+  alias git="cp ${LOFAR20_DIR}/bin/update_submodules.sh ${LOFAR20_DIR}/.git/hooks/post-checkout; cp ${LOFAR20_DIR}/bin/update_submodules.sh ${LOFAR20_DIR}/.git/hooks/post-merge; unalias git; git"
+fi
+
 # This needs to be modified for a development environment.
 # Example:  ~/lofar2.0/tango
 # The current setting is for a production environment.