* Replace the following global variables with named imports:
- Gerrit._pluginLoader
- Gerrit._endpoints
* Update gr-app-global-var-init.js
* Move reset plugins function to test-utils.js
Note: This is not a recommended approach. pluginLoader and endpoints must be
moved to appContext (see todo in the files gr-plugin-loader.js and
gr-plugin-endpoints.js)
Change-Id: Ifc3454c293fc19830f12088168e83748f67d7cff
f97fc6e320