Add webpack.config.js to gitignore.
Add webpack.config.js to gitignore.

bug: 106757419
Change-Id: I210a3ac4b63063579c7513e197a7369567d56eb2

googleinterns/android-studio-figma-overlay,googleinterns/android-studio-figma-overlay,googleinterns/android-studio-figma-overlay,googleinterns/android-studio-figma-overlay