Automatic merge from submit-queue (batch tested with PRs 54488, 54838, 54964). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Add support to for alternative container runtime in `kube-up.sh`

For https://github.com/kubernetes/features/issues/286.

This PR added 4 new environment variables in `kube-up.sh` to support alternative container runtime:
1) `KUBE_MASTER_EXTRA_METADATA` and `KUBE_NODE_EXTRA_METADATA`. Add extra metadata on master and node instance. With this we could specify different cloud-init for a different container runtime, and also add extra metadata for the new cloud-init, e.g. [master.yaml](https://github.com/Random-Liu/cri-containerd/blob/7d739662141cc137f8b1e82a9824b18be2e5df21/test/e2e/master.yaml)
2) `KUBE_CONTAINER_RUNTIME_ENDPOINT`. Specify different sock for different container runtime. It's only used when it's not empty.
3) `KUBE_LOAD_IMAGE_COMMAND`. Specify different load image command for different container runtime.

An example for cri-containerd:
```
export KUBE_MASTER_EXTRA_METADATA="user-data=${GOPATH}/src/github.com/kubernetes-incubator/cri-containerd/test/e2e/master.yaml,cri-containerd-configure-sh=${GOPATH}/src/github.com/kubernetes-incubator/cri-containerd/test/configure.sh"
export KUBE_NODE_EXTRA_METADATA="user-data=${GOPATH}/src/github.com/kubernetes-incubator/cri-containerd/test/e2e/node.yaml,cri-containerd-configure-sh=${GOPATH}/src/github.com/kubernetes-incubator/cri-containerd/test/configure.sh"
export KUBE_CONTAINER_RUNTIME="remote"
export KUBE_CONTAINER_RUNTIME_ENDPOINT="/var/run/cri-containerd.sock"
export KUBE_LOAD_IMAGE_COMMAND="/home/cri-containerd/usr/local/bin/cri-containerd load"
export NETWORK_POLICY_PROVIDER="calico"
```
Signed-off-by: Lantao Liu <lantaol@google.com>

```release-note
none
```
/cc @yujuhong @dchen1107 @feiskyer @mikebrow @abhi @mrunalp @runcom 
/cc @kubernetes/sig-node-pr-reviews