The session id will be used by RollbackManager to simplify the code in
searching for rollbacks and sessions.
(Cherry-picked from 503c1aca53)
Bug: 149663536
Test: m
Merged-In: I94003873f4f244fd6543f22bdbe7b6d4a31aceaf
Change-Id: I94003873f4f244fd6543f22bdbe7b6d4a31aceaf