Adds TransactionManager dumpsys info and cleanups

1) Adds new call sequencing flag for general DSDA development in Telecom
2) Adds a new Transaction History in TransactionManager
  - Keeps track of when a transaction was added/started/completed
  - prints the state of pending and completed transactions for
  dumpsys purposes. Limits the completed transaction queue to 20
  items for now.
  - Modifies SerialTransaction to not remove sub-transactions so that
  we can collect histry about the transaction when finished
3) Cleans up the visibility of some methods and adds flag propogation
changes for testing

Fixes: 315879576
Test: atest TelecomUnitTests:VoipCallTransactionTest
Change-Id: Ifac05d24f70c7e12b1dd5d8f89308d550d3e3ae5