Make Amazon Services interceptors config a list of string

[gsmet]

If it's a list of classes, they are initialized at build time by
SmallRye Config whereas some of the interceptors (the XRay one for
instance) are initialized at runtime.

Making it a list of strings allows to initialize interceptors at runtime
for native executables.

Fixes #13078

[sherl0cks]

@gsmet FYI I was finally able to test this in 1.9.2.Final. The build works, but tracing no longer works with the quarkus created clients.

But does work with clients configured using my own CDI producers

If it helps, here is that config:

    @AlternativePriority(0)
    @ApplicationScoped
    @Produces
    fun dynamoDbAsyncClient(
        @ConfigProperty(name = "aws.region", defaultValue = "us-west-2") awsRegion: String,
        sdkAsyncHttpClient: SdkAsyncHttpClient
    ): DynamoDbAsyncClient {
        return DynamoDbAsyncClient.builder()
            .region(Region.of(awsRegion))
            .httpClient(sdkAsyncHttpClient)
            .overrideConfiguration(
                ClientOverrideConfiguration.builder()
                    // manual instrumentation as described here https://aws.amazon.com/blogs/developer/x-ray-support-for-the-aws-sdk-for-java-v2/
                    .addExecutionInterceptor(TracingInterceptor())
                    .build()
            )
            .build()
    }

I really don't have any idea why this would be, but these are the exact concerns that I had when I wrote #4968 (comment). I'll try to keep testing patches if or @marcinczeczko want to investigate further.