Fix the bundling step to only consider HTML files
Fix the bundling step to only consider HTML files

This fixes the bundler invocation introduced in previous CLs.

R=f07c55753dac44d78e0294a1d64ea321baaa78f4@google.com, fancl@chromium.org

Bug: chromium:986772
Change-Id: Icff84a9d3ea838257f6f129a4f02213deaeafbc8
Reviewed-on: https://chromium-review.googlesource.com/c/catapult/+/1935270
Commit-Queue: Dean Berris <34a37f59e4ade3cf49221306f04217acf3e86255@chromium.org>
Commit-Queue: Andrew Bennetts <f07c55753dac44d78e0294a1d64ea321baaa78f4@google.com>
Reviewed-by: Andrew Bennetts <f07c55753dac44d78e0294a1d64ea321baaa78f4@google.com>
Auto-Submit: Dean Berris <34a37f59e4ade3cf49221306f04217acf3e86255@chromium.org>

catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult,catapult-project/catapult