metropolis: Lock down visibility rules

This formalizes the package structure introduced by D683.

Test Plan: Pure refactor, CI only.

X-Origin-Diff: phab/D684
GitOrigin-RevId: 574aa14c71faf94f4a5c02a2110e2e3fef7d36ac
diff --git a/metropolis/test/e2e/k8s_cts/BUILD.bazel b/metropolis/test/e2e/k8s_cts/BUILD.bazel
index 0e43c24..2932758 100644
--- a/metropolis/test/e2e/k8s_cts/BUILD.bazel
+++ b/metropolis/test/e2e/k8s_cts/BUILD.bazel
@@ -22,7 +22,7 @@
     base = ":kubectl_in_path",
     binary = "@io_k8s_kubernetes//test/e2e:_go_default_test-pure",
     pure = "on",
-    visibility = ["//visibility:public"],
+    visibility = ["//metropolis/node:__pkg__"],
 )
 
 go_library(
@@ -51,5 +51,5 @@
         "@com_github_bonzini_qboot//:qboot-bin",
     ],
     embed = [":go_default_library"],
-    visibility = ["//visibility:public"],
+    visibility = ["//visibility:private"],
 )
diff --git a/metropolis/test/e2e/preseedtest/BUILD.bazel b/metropolis/test/e2e/preseedtest/BUILD.bazel
index 41b32e3..d33bcbc 100644
--- a/metropolis/test/e2e/preseedtest/BUILD.bazel
+++ b/metropolis/test/e2e/preseedtest/BUILD.bazel
@@ -12,5 +12,5 @@
     name = "preseedtest",
     embed = [":go_default_library"],
     pure = "on",
-    visibility = ["//visibility:public"],
+    visibility = ["//metropolis/node:__pkg__"],
 )