This causes issues when the app is vulcanized and the paths are
different as a result. The async/defer attributes will ensure
the script does not block parsing of the page.
Adds a flag to the Vulcanize rule that excludes HLJS. Confirmed that the
tag is ignored by Vulcanize phase in the compiled WAR file. Confirmed
that the `onload` case functions as expected via browser throttling.
Change-Id: Ie9603a5a07d4bae198ccc1ee56f408bfa0d37d49