[TECHNICAL] Unit tests for repository classes - Part 2

[JuancaG05]

Epic:

• https://github.com/owncloud/android/issues/4063

In this issue we'll address the unit tests for the class:

• OCFileRepository

Remember we want to create unit tests that check that every method returns the expected result and verify that every method calls the corresponding methods of other classes.

TASKS

• [x] Research (if needed)
• [x] Create branch technical/testing_repositories_2
• [x] Development tasks
  • [x] Create unit tests for OCFileRepository
• [ ] Code review and apply changes requested
• [ ] Merge branch technical/testing_repositories_2 into master