Added viewLifecycleOwner to the observers inside Fragments

[gastsail]

Added viewLifecycleOwner to the observers inside fragments to handle the viewmodel operations withing the lifecycle of the Fragment.

This prevents resuscribing to the observers, hence preventing them to be notified twice, also, the observers will be removed depending on the lifecycle of the Fragment that subscribes to it.

[gastsail]

Can we check on this @yigit ? Thanks