fix(input): fix display of ion-input in narrow ion-item in Firefox

[pwespi]

Short description of what this resolves:

fix display of ion-input in narrow ion-item in Firefox

Ionic Version: 4

Fixes: #16977

[manucorporat]

cc @brandyscarney

[pwespi]

I just tested with the latest @ionic/core@dev and the issue is still there.
This PR should still work.

[brandyscarney]

@pwespi Thanks for the PR! Could you add a code example to one of the e2e tests? Maybe this one: https://github.com/ionic-team/ionic/blob/master/core/src/components/input/test/basic/index.html

That will make it easy for us to test it out and make sure it doesn't have a regression in the future. 🙂

[brandyscarney]

Also, here are some docs on previewing changes if you need them: https://github.com/ionic-team/ionic/blob/master/.github/CONTRIBUTING.md#preview-changes

[pwespi]

@brandyscarney I have added a code example.
Note that the issue only occurs in Firefox (tested on Windows 10, Firefox 64.0.2)

[brandyscarney]

@pwespi Thanks for adding the code example and for the fix! Once the build finishes I can merge this. 🙂