GCE: Add TARGET and FS to image family

GCE image family is meant to be unique per set of image characteristics
so that a user can create instances using the image family instead of the
image name to reliably get a similar image with updated software, but no
other changes.

Without this change, the instances create API would select the most recent
non-deprecated image matching the name, regardless of architecture or
filesystem.

release/Makefile.gce

@@ -16,7 +16,7 @@ GCE_BUCKET?=
 GCE_LICENSE?=
 
 .if !defined(GCE_FAMILY) || empty(GCE_FAMILY)
-GCE_FAMILY=		${TYPE:tl}-${REVISION:S,.,-,}
+GCE_FAMILY=		${TYPE:tl}-${REVISION:S,.,-,}-${TARGET}
 .endif
 
 .if ${BRANCH} == "STABLE" || ${BRANCH} == "CURRENT" || ${BRANCH} == "PRERELEASE"
@@ -74,7 +74,7 @@ gce-do-upload-${_FS}:
 	/usr/local/bin/gsutil cp ${.OBJDIR}/${GCE_TARGET_${_FS}}.tar.gz \
 		gs://${GCE_BUCKET}/
 	/usr/local/bin/gcloud compute images create ${GCE_TARGET_${_FS}} \
-		--family=${GCE_FAMILY}${GCE_FAMILY_SUFX} ${GCE_LICENSE} \
+		--family=${GCE_FAMILY}-${_FS}${GCE_FAMILY_SUFX} ${GCE_LICENSE} \
 		--guest-os-features=GVNIC,UEFI_COMPATIBLE \
 		--source-uri gs://${GCE_BUCKET}/${GCE_TARGET_${_FS}}.tar.gz
 	touch ${.OBJDIR}/${.TARGET}