build-unit-test-docker: Run ldconfig

The preinstalled packages are copied to /usr/local but ld is not aware
of these libraries until ldconfig is run. This makes the container more
useful for interactive use out of the box.

Tested:
== Before ==
docker$ ldd /usr/local/lib/libboost_coroutine.so | grep 'not found'
        libboost_context.so.1.84.0 => not found

== After ==
docker$ ldd /usr/local/lib/libboost_coroutine.so | grep 'not found'
docker$

Change-Id: I3f6508ad6068df03206b6c405532c0230dd95d8d
Signed-off-by: Jonathan Doman <jonathan.doman@intel.com>
1 file changed