6875: Remove service-glean's hard-dependency on httpurlconnection r=Dexterp37 a=badboy

Remove service-glean's hard-dependency on httpurlconnection

We still test with it, so we keep it around.

*BREAKING CHANGE*:

Users will need to supply a configuration with a ping uploader to Glean
now.
A default lib-fetch-httpurlconnection implementation can be used like
this:

```kotlin
import mozilla.components.lib.fetch.httpurlconnection.HttpURLConnectionClient;
import mozilla.components.service.glean.config.Configuration;
import mozilla.components.service.glean.net.ConceptFetchHttpUploader;

val config = Configuration(httpClient = ConceptFetchHttpUploader(lazy { HttpURLConnectionClient() }))
Glean.initialize(context, true, config)
```

For Java this becomes:

```java
import mozilla.components.lib.fetch.httpurlconnection.HttpURLConnectionClient;
import mozilla.components.service.glean.config.Configuration;
import mozilla.components.service.glean.net.ConceptFetchHttpUploader;

ConceptFetchHttpUploader httpClient = ConceptFetchHttpUploader.fromClient(new HttpURLConnectionClient());
Configuration config = new Configuration(httpClient);
Glean.INSTANCE.initialize(context, true, config);
```

Fixes #6660 (at least partly)

I'm not familiar enough with service-experiments, so @travis79

 would need to take a look.

cc @pocmo for visibility.




Co-authored-by: Jan-Erik Rediger <janerik@fnordig.de>