fix(test): Fix the `attempt to use webcam for avatar` functional test.
fix(test): Fix the `attempt to use webcam for avatar` functional test.

The `#camera span` element was removed with #3379.
Look for the `#camera` element only.

fixes #3455

swatilk/fxa-content-server,vladikoff/fxa-content-server,mozilla/fxa-content-server,shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,swatilk/fxa-content-server,shane-tomlinson/fxa-content-server,mozilla/fxa-content-server,swatilk/fxa-content-server,shane-tomlinson/fxa-content-server,vladikoff/fxa-content-server,vladikoff/fxa-content-server