[Paradise] Pass bool to controller on whether to show error or feedback

Previously we used empty vector to do if to show error dialog, but in
this way the dialog did not know how many cards user selected to upload,
thus did not know what error message to show (This card vs These cards).

Bug: 897998
Change-Id: If4d65e5330ab60f0645dd5d5a45d3d15c9a75ae1
Reviewed-on: https://chromium-review.googlesource.com/c/1366790
Reviewed-by: Evan Stade <estade@chromium.org>
Reviewed-by: Jared Saul <jsaul@google.com>
Reviewed-by: Moe Ahmadi <mahmadi@chromium.org>
Reviewed-by: Tao Bai <michaelbai@chromium.org>
Commit-Queue: Jason Guo <jiahuiguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615238}
14 files changed