Bump docker install version w/ RKE1 clusters; `17.03.2` => `20.10`

[Josh-Diamond]

When provisioning a downstream RKE1 cluster w/ docker install from TF rancher2 provider, docker 17.03.2 is installed.

When provisioning a downstream RKE1 cluster w/ docker install from RancherUI, docker 20.10 is installed.

This issue was created to bump the docker install version with TF rancher2 provider to 20.10

[Josh-Diamond]

Test Plan:

1. Fresh install of rancher v2.7-head
2. With TF, deploy a downstream RKE1 cluster - [DO NOT SET engine_install_url on node_template resource]
3. Observe docker install version; expected to be 20.10

---

Workaround for this, in the meantime would be to add the following to the rancher2_node_template resource: engine_install_url = "https://releases.rancher.com/install-docker/20.10.sh"

[a-blender]

@Josh-Diamond This is not ready to test

[a-blender]

Dev-validated on rancher v2.7-head

• [x] RKE1 EC2 cluster via terraform, no AMI - rancher defaults to docker 20.10
• [x] RKE1 EC2 cluster via terraform, AMI eli-kube-dock-server ami-0e3c799b78951f41b - rancher installs docker 20.10 on the nodes
• [x] RKE1 EC2 cluster via terraform, no AMI, engine_install_url = https://releases.rancher.com/install-docker/20.10.9.sh - rancher installs docker 20.10.9 on the nodes

main.tf

terraform {
  required_providers {
      rancher2 = {
        source  = "terraform.example.com/local/rancher2"
        version = "1.0.0"
      }
  }
}
provider "rancher2" {
  api_url   = var.rancher_api_url
  token_key = var.rancher_admin_bearer_token
  insecure  = true
}
data "rancher2_cloud_credential" "rancher2_cloud_credential" {
  name = var.cloud_credential_name
}
resource "rancher2_cluster" "rancher2_cluster" {
  name = var.cluster_name
  rke_config {
    kubernetes_version = "v1.24.4-rancher1-1"
    network {
      plugin = var.network_plugin
    }
  }
}
resource "rancher2_node_template" "rancher2_node_template" {
  name = var.node_template_name
  amazonec2_config {
    access_key     = var.aws_access_key
      secret_key     = var.aws_secret_key
      region         = var.aws_region
          ami            = var.aws_ami
      security_group = [var.aws_security_group_name]
      subnet_id      = var.aws_subnet_id
      vpc_id         = var.aws_vpc_id
      zone           = var.aws_zone_letter
      root_size      = var.aws_root_size
      instance_type  = var.aws_instance_type
  }
}
resource "rancher2_node_pool" "pool1" {
  cluster_id       = rancher2_cluster.rancher2_cluster.id
  name             = "pool1"
  hostname_prefix  = "tf-pool1-"
  node_template_id = rancher2_node_template.rancher2_node_template.id
  quantity         = 1
  control_plane    = false
  etcd             = true 
  worker           = false 
}
resource "rancher2_node_pool" "pool2" {
  cluster_id       = rancher2_cluster.rancher2_cluster.id
  name             = "pool2"
  hostname_prefix  = "tf-pool2-"
  node_template_id = rancher2_node_template.rancher2_node_template.id
  quantity         = 1
  control_plane    = true
  etcd             = false 
  worker           = false 
}
resource "rancher2_node_pool" "pool3" {
  cluster_id       = rancher2_cluster.rancher2_cluster.id
  name             = "pool3"
  hostname_prefix  = "tf-pool3-"
  node_template_id = rancher2_node_template.rancher2_node_template.id
  quantity         = 1
  control_plane    = false
  etcd             = false 
  worker           = true 
}

terraform.tfvars

# Rancher specific variables
rancher_api_url                          = "<rancher API url>"
rancher_admin_bearer_token               = "<rancher bearer token>"
cloud_credential_name                    = "<cloud credential name>"

# AWS specific variables
aws_access_key                           = "<AWS access key>"
aws_secret_key                           = "<AWS secret key>"
aws_instance_type                        = "t3.medium"
aws_ami                  = ""
aws_region                               = "us-east-2"
aws_security_group_name                  = "rancher-nodes"
aws_subnet_id                            = "subnet-xxxxxx"
aws_vpc_id                               = "vpc-xxxxxxx"
aws_zone_letter                          = "a"
aws_root_size                            = "80"

# RKE1 specific variables
cluster_name                             = "ablender-rke1"
network_plugin                           = "canal"
node_template_name                       = "tf-rke1-template"

# Testing specific variables
expected_provider                        = "rke"
expected_state_active                    = "active"

RKE1 EC2 cluster, no AMI

RKE1 EC2 cluster, AMI eli-kube-dock-server ami-0e3c799b78951f41b (AMI had docker version 20.10.12)

RKE1 EC2 cluster, no AMI, engine_install_url = https://releases.rancher.com/install-docker/20.10.9.sh