Add several environment variables to Concourse Filter whitelist
Add several environment variables to Concourse Filter whitelist

- BUILDPACK_DEPENDENCIES_HOST_DOMAIN,PIVNET_ADDRESS,GITHUB_URL,
PIVNET_PRODUCT_NAME,GOPATH,TMPDIR
- Reformat CREDENTIAL_FILTER_WHITELIST into multiline string for
  readability

[#127361305]

Signed-off-by: Sam Smith <03a07629efb0a02c7bbe7cc340a4243da1ab861a@gmail.com>

orange-cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,orange-cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci,orange-cloudfoundry/buildpacks-ci,cloudfoundry/buildpacks-ci