Rename files to preserve history

Test\Eslint fail - this is expected.

Change-Id: Ied2e89553cda4ac562ad28e2e54d6f7709e43fc0
diff --git a/polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences.js b/polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences.ts
similarity index 100%
rename from polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences.js
rename to polygerrit-ui/app/elements/settings/gr-edit-preferences/gr-edit-preferences.ts