build-unit-test-docker: Fix stdplus gtest support lib
build-unit-test-docker: Fix stdplus gtest support lib

This lib provides some support functions for making googletest routines
more convenient and is used by phosphor-networkd.

Change-Id: I58855538eb94ca7c128c6cee3812cbea09177659
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/openbmc-build-scripts,openbmc/openbmc-build-scripts