Add a flush function that returns success. This is
needed to pass VTS testing.
Change-Id: I0550eb39694b4bf33ed7ba872107a135edf27a71
Reviewed-on: https://gerrit.mot.com/1759290
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Konstantin Makariev <kmakariev@motorola.com>
Submit-Approved: Jira Key