Camera: Switch the reader callback when the sequence ends

Depending on timing the first captured buffer from an internal
repeating request can be incorrectly propagated to the client
preview surface. This can happen, if the first 'onCaptureStarted'
callback gets delayed and executes after the first buffer from the
internal request gets queued in the camera preview output surface.
Proactively switch the camera preview output image reader callback
to loopback after the current capture sequence ends.

Bug: 179450326
Test: Camera CTS
Change-Id: I8232ea5171a0205da5705b6af5fdd3cdab297335