Fix how we check for dynamic values in message templates.
In the experimental api we set a static message under the assumption it was not a dynamic template in cases where the whole
message was a single data value.
Checklist
[x] My code follows the style guidelines of this project
[x] I have commented my code, particularly in hard-to-understand areas
[x] I have made corresponding changes to the documentation
[x] I have made corresponding change to the default configuration files
[x] I have added tests that prove my fix is effective or that my feature works
[x] I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.
Proposed commit message
Checklist
CHANGELOG.next.asciidoc
orCHANGELOG-developer.next.asciidoc
.Related issues