Verify UTC zoneid as normalized object

[aguibert]

Recently it was pointed out by @martijndwars in this Yasson issue that we were not serializing ZoneId.of("UTC") correctly:

JSON-B spec section 3.5.3 states:

Implementations MUST support the deserialization of any time zone ID format specified in java.time.ZoneId into a field or property of type java.time.ZoneId. The serialization format of java.time.ZoneId is the normalized zone ID as specified in java.time.ZoneId.

Martijn pointed out the following in his issue:

The normalized part makes a difference when you have a ZoneId.of("UTC"), for example. The zone ID is "UTC", but the normalized zone ID is "Z", as shown by this jshell session:

jshell> import java.time.*;

jshell> ZoneId.of("UTC").getId()
$2 ==> "UTC"

jshell> ZoneId.of("UTC").normalized().getId()
$3 ==> "Z"

One of the Yasson contributors, @Degubi, fixed this issue in a Yasson PR.

When running the Yasson TCK with this change, I noticed that one test was expecting the incorrect behavior. It was expecting ZoneId.of("UTC") to be serialized as the string "UTC", but it should be normalized to "Z"