Summary:
This exposes a transactions state through a public api rather than through a public member variable. I also do some name refactoring.
ExecutionStatus => TransactionState
exec_status_ => trx_state_
Test Plan: It compiles and transaction_test passes.
Reviewers: IslamAbdelRahman
Reviewed By: IslamAbdelRahman
Subscribers: andrewkr, mung, dhruba, sdong
Differential Revision: https://reviews.facebook.net/D64689