There is a compiler transform that downlevels Angular class decorators
to static properties so that metadata is available for JIT compilation.
The transform was supposed to ignore non-Angular decorators but it was
actually completely dropping decorators that did not conform to a very
specific syntactic shape (i.e. the decorator was a simple identifier, or
a namespaced identifier).
This commit ensures that all non-Angular decorators are kepts as-is
even if they are built using a syntax that the Angular compiler does not
understand.
Fixes#39574
PR Close#39577