m/node/kubernetes: fix PV mount flags and add e2e test

Mount flags did not work because of two problems:
- The provisioner did not copy them from the StorageClass to the
  PersistentVolume.
- The CSI server used = instead of |= when adding flags, so only one of
  the flags was added or removed.

There was an existing e2e test for PVs, however this only created the
PVC/PV without even attaching it to a container. I extended this test to
attach the PV and check from inside the container that it has the
expected mount flags and quota.

The existing e2e test also created a block PV, however attaching a block
PV to a container was not tested and is apparently broken, so I removed
this test for now.

Change-Id: Ie14adfafd333eab38d2b5f1b4ce8a2aa8795eae0
Reviewed-on: https://review.monogon.dev/c/monogon/+/3613
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
Tested-by: Jenkins CI
diff --git a/metropolis/test/e2e/BUILD.bazel b/metropolis/test/e2e/BUILD.bazel
index ecbdc97..883dcb8 100644
--- a/metropolis/test/e2e/BUILD.bazel
+++ b/metropolis/test/e2e/BUILD.bazel
@@ -4,6 +4,7 @@
     name = "testimages_manifest",
     images = [
         "//metropolis/test/e2e/selftest:selftest_image",
+        "//metropolis/test/e2e/persistentvolume:persistentvolume_image",
         "//metropolis/test/e2e/httpserver:httpserver_image",
     ],
     visibility = [