Quarkus knative-tutorial-greeter not working with structured encoded events

[matejvasek]

The knative-tutorial-greeter app works only with binary encoded events.
It should work with structured encoded events too.

[matejvasek]

/cc @kameshsampath

[matejvasek]

/kind bug

[sebastienblanc]

@matejvasek Could you provide more information for this bug ? Or even better a PR :) ?