[composebox] Update AIM url to include lens context if file uploaded.

This CL adds lens specific params to the AIM url if a file was uploaded.
This currently only supports only single file upload, so if their are
multiple files uploaded, the last file in the active file map is used.

TBD on whether we need lns_surface, but for now Web doesn't use it and
adding it causes AIM to not return a message.

Change-Id: Ied31c9be4c261305a4944986c9c74ea9a87c1b81
Bug: 428067264
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6697055
Reviewed-by: Duncan Mercer <mercerd@google.com>
Commit-Queue: Nihar Majmudar <niharm@google.com>
Cr-Commit-Position: refs/heads/main@{#1481808}