WebUI Polymer2: Remove Polymer1 support, part 1.

Remove
 - webui_polymer1_browser_tests
 - webui_polymer1_interactive_ui_tests

suites from buildbot configuration.

Bug: 944281,893078
Change-Id: I84808a63c8c91c1769f225f9a7e4c8cfea9ef344
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1533085
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652982}
14 files changed