Refactoring suggestions for network attributes related stuff

[surbhiia]

Currently, the project has the following modules/folders related to network attributes:

• Network Change Instrumentation Module - Hosts files related to the instrumentation itself (instrumenter creation, attribute extraction, registering network change listener in CurrentNetworkProvider service etc)
• CurrentNetworkProvider Service (folder in services module)- Hosts files related to the service that keeps track of the CurrentNetwork and notifies all listeners onNetworkchange.
• Network data model and CurrentNetworkAttributesExtractor (folder in common module)
• NetworkAttributesSpanAppender (folder in core module) - Internal to opentelemetry-android. Provides a custom span processor for adding network attributes to all spans.

The above division of separate work in separate folders/modules makes sense and is also needed to have a clean dependency graph among them all. There are a few minor things I think we should refactor to make it more readable/usable:

• Rename instrumentation module to something better than what it currently is - "network". It can be confused for network request interception. Can we rename it to something like - "networkchange"?
• Can we drop "internal/features" or just drop "features" if we still want to keep it internal from /common/main/java/io/opentelemetry/android/common/internal/features/networkattributes/?
• Extract NetworkAttributesSpanAppender and all other span processors like ScreenAttributesSpanProcessor, SessionIdSpanAppender and GlobalAtributesSpanAppender in their own module to allow for reusability? (Contrary to the span processors, all log processors do have a house at a single place. They can perhaps be extracted in the same new module or a separate one for them?)
• A small duplication I noticed - Instead of duplicating NETWORK_STATUS_KEY in NetworkApplicationListener,, NetworkChangeMonitorTest can utilize the same from NetworkChangeAttributesExtractor if feasible.