Add unittest to create/goldfish*

Coverage for create/goldfish_remote_image_remote_instance.py : 54 -> 100%
Coverage for create/goldfish_remote_image_remote_host.py : 69 -> 100%

Bug: 202820293
Test: . run_test.sh
Change-Id: I24f9e3de5d3c791b42a50cf0ffe8ce5e83d755bb
2 files changed