Rename Context Menu in Switch Access for clarity.

Also renames the panel.* files to menu_panel.*

Bug: None
Change-Id: I12d9dfde8eb58690bdc69577b8e1ec94aec460d3
Reviewed-on: https://chromium-review.googlesource.com/c/1406206
Commit-Queue: Anastasia Helfinstein <anastasi@google.com>
Reviewed-by: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622238}
12 files changed