Camera: Support common outputs between regular and extension sessions

Camera clients must be able to re-use the same output/outputs between
regular capture and extension sessions.
Re-shuffle the extension logic so that user registered outputs are
always accessed/connected to after the camera device configures its
streams.
Additionally disconnect any user registered outputs as soon as the
client requests a new regular capture session.

Bug: 194508189
Test: Partner testing,
Camera CTS

Change-Id: I112ad916e5d019d313767d3a0b0454165a6feb12