Camera: Turn off torch at provider startup

Flashlight could be stuck at ON after system_server crashes
(which results in cameraserver to restart).
As a workaround, turn flash off at the provider start.

Alternative considered: restart HAL process when cameraserver
restarts. However, even with that, some device still fails to
turn off flashlight.

Test: Camera CTS, kill system_server with flash on
Bug: 247038031
Change-Id: I8a49ce8a541dc0537348dc16b3b48b96b10c89f6