Backport of Fix Sync Catalog ACL Token Environment Var Name into release/1.0.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #2068 to be assessed for backporting due to the inclusion of the label backport/1.0.x.

The below text is copied from the body of the original PR.

---

Changes proposed in this PR:

• Change the environment variable name for the ACL token secret to match what is expected by the control plane. (Fixes Helm: ACL token env var is incorrect for Sync Catalog  #1891)
  • Currently, the chart is setting the CONSUL_HTTP_TOKEN environment variable which is not used by the Consul client within the control plane.
  • The control plane is instead reading CONSUL_ACL_TOKEN:

    consul-k8s/control-plane/subcommand/flags/consul.go

    Lines 153 to 155 in 11f842c

    	fs.StringVar(&f.Token, "token", os.Getenv(ACLTokenEnvVar),
    	"ACL token to use for connection to Consul."+
    	"This can also be specified via the CONSUL_ACL_TOKEN environment variable.")

How I've tested this PR:

• Deployed the chart with the included changes and observed the control plane properly loaded the provided Consul token and used it to register services.

How I expect reviewers to test this PR:

• Deploy an external Consul server that has ACLs enabled.
• Create a policy and token with the proper permissions to run the catalog sync agent.
• Populate the token secret into a K8S secret and provide that secret name and key to the chart.
• Verify that the sync catalog agent loads the token and is able to register services.

Checklist:

• Tests updated
• CHANGELOG entry added

  HashiCorp engineers only, community PRs should not add a changelog entry.
  Entries should use present tense (e.g. Add support for...)

---

Overview of commits

• 9932219 - 2b74c96