msm: camera: sensor: Reset actuator flush requestId

When camera module shut down happens reset the
last flush request ID for the new session to
continue as fresh start.

CRs-Fixed: 2822543
Change-Id: Ic5b43d7acaeb7e7b6999c02cbb4654598469638b
Signed-off-by: Sureshnaidu Laveti <lsuresh@codeaurora.org>