Avoid casting RepositoryManager to LocalDiskRepositoryManager

Inject directly the expected class of LocalDiskRepositoryManager
without assuming that the one provided by the AbstractDaemonTest.

The Change I8d288fa3 will replace the repository manager
with a wrapping repository tracking system, therefore the casting
may not be satisfied anymore and it may fail at runtime.

Release-Notes: skip
Change-Id: I8e410ae6a489b1127ef09d4c203ab9aa1d711d8d