[Snap/Live] Fix "snap to album" with multiple channels

Previously, only snap images were getting their summary metadata set; images
generated with live mode did not have this information. This was harmless
except for when the "snap to album" button was clicked after having run live
mode: AcquisitionManager would try to access the image's summary metadata to
determine how many channels there are, fail, and in the case where there was
more than one channel, assign the two channels to separate timepoints.

Now we set summary metadata for all images in the snap/live display, which
fixes that issue (and may fix others as well).

git-svn-id: https://valelab.ucsf.edu/svn/micromanager2/trunk@14643 d0ab736e-dc22-4aeb-8dc9-08def0aa14fd