hterm: prefs: make listProfiles take the storage
hterm: prefs: make listProfiles take the storage

Rather than go through hterm.defaultStorage, have the caller pass in
the storage they want to query.  We only have one user of this API,
and it should be passing in the storage now anyways.  This also helps
us get rid of the global hterm.defaultStorage variable.

Change-Id: I07528022311b0d7c3cab4e2fa3e65a467126836e
Reviewed-on: https://chromium-review.googlesource.com/c/apps/libapps/+/2494362
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Joel Hockey <9ecfc52dc2ffef73afac73f3495f294aeddf1231@chromium.org>

chromium/hterm,chromium/hterm,chromium/hterm,chromium/hterm