In v2.x, users had to annotate classes that they intended to use as tokens with `@Injectable`. This is no longer required in v4.x for tokens,
and we now require the constructor parameters of classes annotated
with `@Injectable` to be statically analyzable by ngc.
This commit reduces the error into a warning
if the constructor parameters do not meet this condition.
DEPRECATION:
- Classes annotated with `@Injectable` but whose constructor’s parameter types
are not statically analyzable by ngc will produce a warning.
Closes#15003
5c34066058