Qute - methods on Object not resolved for types declared using interfaces

[Maldivia]

Describe the bug
Given a template with

{@java.util.List obj}
{obj.toString()}

results in a BuildException with:

[1] Incorrect expression: obj.toString()
	- property/method [toString()] not found on class [java.util.List] nor handled by an extension method
	- found in template [hello.html] on line 2

The above works as expected if it's a concrete type, for instance:

{@java.util.ArrayList obj}
{obj.toString()}

Environment (please complete the following information):
Quarkus 1.3.0.Final
Java 11.0.6

[quarkusbot]

/cc @mkouba