Add minimal functionality test for k8s control plane

Basic functionality test that sends the bootstrap RPC call,
waits for the k8s control plane to come up and runs a simple
kubectl command (that is expected to fail).

Adds reflection to the server to make grpc_cli easier to use.

Test Plan:
Ran `:launch` (because we modified its config) and `:test_boot`,
saw a nicely booted k8s cluster:

{P90}

X-Origin-Diff: phab/D275
GitOrigin-RevId: fe01e3f3ed09877aa76c15946664c9d9bdc4751b
diff --git a/core/scripts/BUILD b/core/scripts/BUILD
index b03bc49..c023ed4 100644
--- a/core/scripts/BUILD
+++ b/core/scripts/BUILD
@@ -1,10 +1,24 @@
-sh_binary(
-    name = "launch",
-    srcs = ["launch.sh"],
+
+sh_library(
+    name = "vm_deps",
     data = [
         "@//core:image",
         "@//core:swtpm_data",
         "@edk2//:firmware",
+    ]
+)
+
+sh_binary(
+    name = "launch",
+    srcs = ["launch.sh"],
+    deps = [":vm_deps"],
+)
+
+sh_library(
+    name = "test_deps",
+    data = [
+        ":launch",
+        "//:kubectl",
     ],
 )
 
@@ -14,5 +28,5 @@
     srcs = ["test_boot.sh"],
     # expects wants a pty, which do not exist in the sandbox
     tags = ["local"],
-    deps = [":launch"],
+    deps = [":test_deps", ":vm_deps"],
 )