KNOX-3295: Set default type to JWT in issued knox token headers

[hanicz]

KNOX-3295 - Set default type to JWT on issued tokens

What changes were proposed in this pull request?

Sets the default type in JWT headers to JWT

How was this patch tested?

Tested locally with the sandbox topology

<service>
        <role>KNOXTOKEN</role>
        <param>
            <name>knox.token.ttl</name>
            <value>36000000</value>
        </param>
        <param>
            <name>knox.token.audiences</name>
            <value>tokenbased</value>
        </param>
        <param>
            <name>knox.token.target.url</name>
            <value>https://localhost:8443/gateway/tokenbased</value>
        </param>
        <param>
            <name>knox.token.exp.server-managed</name>
            <value>true</value>
        </param>
</service>

curl -ivku admin:admin-password https://localhost:8443/gateway/sandbox/knoxtoken/api/v1/token

{
  "jku": "https://localhost:8443/gateway/sandbox/knoxtoken/api/v1/jwks.json",
  "kid": "_AGCGyQJ0pIceEVPCmVMkTTC4DddcGG_5XQAhgImjyw",
  "typ": "JWT",
  "alg": "RS256"
}

Integration Tests

N/A

UI changes

N/A

[smolnar82]

Some minor changes requested.

[smolnar82]

LGTM

[github-actions]

Test Results

7 tests   7 ✅  1s ⏱️
1 suites  0 💤
1 files    0 ❌

Results for commit 8f8be64.