feat: AndroidUrlMediaSource, Tests, Comments and Refactoring for MediaSourceConfiguration classes. #3642
  Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
Issue #, if available:
No GitHub issues, but this is a production issue I have helped a customer with. This PR is based on the solution I gave to the customer and the same has been tested and verified by the customer as well.
Description of changes:
Recently, we had a customer who wanted to use video files/urls as the source instead of camera. This solution implements a new AndroidUrlMediaSource class to facilitate this. Apart from this class, a number of supporting changes also had to be added such as extracting common code in MediaSourceConfiguration into AbstractMediaSourceConfiguration class. I have also added extensive code documentation for all new and exisiting files that were modified.
Kindly review, as this can help a lot of customers.
Please let me know if there are questions, suggestions for change etc.
By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.