[Fix] Handle form input on Android-Web

[DanielMuller]

Addresses issue #3598

Description of changes:
On Android-Web, v-model is not updated with keyboards using IME, unless a space is typed as described in vuejs/vue#8231 and vuejs/vue#8723
Which leads to this.signInUsername to stay empty in components/authenticator/SignIn.vue

Adding v-on:input as suggested by vuejs/vue#8231 (comment) fixes the issue for Android-Web without any impact on Desktop.

Tested on Chrome-Android and Chrome Desktop.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #4292 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4292   +/-   ##
=======================================
  Coverage   78.72%   78.72%           
=======================================
  Files         165      165           
  Lines        9032     9032           
  Branches     1820     1820           
=======================================
  Hits         7110     7110           
  Misses       1789     1789           
  Partials      133      133

Impacted Files	Coverage Δ
...vue/src/components/authenticator/UsernameField.vue	57.14% <ø> (ø)	⬆️
...fy-vue/src/components/authenticator/PhoneField.vue	88.88% <ø> (ø)	⬆️

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[jordanranz]

LGTM thanks for contributing!

[github-actions]

This pull request has been automatically locked since there hasn't been any recent activity after it was closed. Please open a new issue for related bugs.

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