This change replace all HTML imports with es6-modules. The only exceptions are:
* gr-app.html file, which can be deleted only after updating the
gerrit/httpd/raw/PolyGerritIndexHtml.soy file.
* dark-theme.html which is loaded via importHref. Must be updated manually
later in a separate change.
This change was produced automatically by ./es6-modules-converter.sh script.
No manual changes were made.
Change-Id: I0c447dd8c05757741e2c940720652d01d9fb7d67
daf0ec9543