chore: Fix internal tslint errors

[acdvorak]

Refs #4225

[codecov-io]

Codecov Report

Merging #4440 into feat/typescript will decrease coverage by 0.01%.
The diff coverage is 88.88%.

@@                 Coverage Diff                 @@
##           feat/typescript    #4440      +/-   ##
===================================================
- Coverage            99.06%   99.05%   -0.02%     
===================================================
  Files                  130      130              
  Lines                 6230     6230              
  Branches               811      812       +1     
===================================================
- Hits                  6172     6171       -1     
- Misses                  57       58       +1     
  Partials                 1        1

Impacted Files	Coverage Δ
packages/mdc-tab-indicator/fading-foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-tabs/tab/foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-select/foundation.ts	97.6% <ø> (ø)	⬆️
packages/mdc-textfield/foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-snackbar/foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-top-app-bar/foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-linear-progress/foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-icon-button/foundation.ts	100% <ø> (ø)	⬆️
packages/mdc-dom/ponyfill.ts	100% <ø> (ø)	⬆️
packages/mdc-grid-list/foundation.ts	100% <ø> (ø)	⬆️
... and 44 more

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[mdc-web-bot]

All 624 screenshot tests passed for commit b51914c vs. feat/typescript! 💯🎉

[mdc-web-bot]

All 624 screenshot tests passed for commit 9d38fa2 vs. feat/typescript! 💯🎉