fix(demos): Fix NPEs in drawer demos

[acdvorak]

To repro:

1. View the Temporary Drawer demo page in any browser
2. Open the dev tools
3. Open the drawer by clicking on the toolbar menu icon
4. Click on a blank part of the drawer (NOT on a list item)

[codecov-io]

Codecov Report

❗ No coverage uploaded for pull request base (master@0b4b870). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master    #1946   +/-   ##
=========================================
  Coverage          ?   99.43%           
=========================================
  Files             ?       84           
  Lines             ?     3721           
  Branches          ?      484           
=========================================
  Hits              ?     3700           
  Misses            ?       21           
  Partials          ?        0

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0b4b870...b0323db. Read the comment docs.