[CDM perm sync] Send and receive messages integration

Send message flow (will remain unchanged):
1. A companion app calls startSystemDataTransfer
2. SystemDataTransferProcessor creates the permission backup file and
   send it CompanionMessageProcessor
3. CompanionMessageProcessor paginate the message and send them to
   CompanionSecureCommsManager
4. CompanionSecureCommsManager encrypts the messages and send them to the
   app.
This CL changes the logic to bind to the app if it's unbind. Previously
CompanionSecureCommsManager would throw an exception if it's unbind.

Receive message flow (newly integrated in this CL):
1. A companion app calls dispatchMessageToSystem
2. CompanionSecureCommsManager receives the message and decrypts it.
3. CompanionMessageProcessor receives the message via listener
   and may return the complete message to SystemDataTransferProcessor
   via listener.
4. SystemDataTransferProcessor processes the decrypted complete message.

Bug: 231474219

Test: manually tested the sender and receiver flows.
Change-Id: I0eb920103080fcb708614e636c6afec4fc69d92c