fix(#2229): dropdown height issue

[syedszeeshan]

Before (the change)

After (the change)

Make sure that you've checked the boxes below before you submit the PR

• I have read and followed the setup steps
• I have created necessary unit tests
• I have tested the functionality in both React and Angular.

Steps needed to test

[ArakTaiRoth]

@syedszeeshan There appears to still be a slight discrepancy, tested in Angular with the following code:

<h2>What is your date of birth?</h2>
<goa-block>
  <goa-form-item label="Day">
    <goa-input width="50px" />
  </goa-form-item>
  <goa-form-item label="Month">
    <goa-dropdown>
      <goa-dropdown-item value="January" label="January" />
      <goa-dropdown-item value="February" label="February" />
      <goa-dropdown-item value="March" label="March" />
      <goa-dropdown-item value="April" label="April" />
      <goa-dropdown-item value="May" label="May" />
      <goa-dropdown-item value="June" label="June" />
      <goa-dropdown-item value="July" label="July" />
      <goa-dropdown-item value="August" label="August" />
      <goa-dropdown-item value="September" label="September" />
      <goa-dropdown-item value="October" label="October" />
      <goa-dropdown-item value="November" label="November" />
      <goa-dropdown-item value="December" label="December" />
    </goa-dropdown>
  </goa-form-item>
  <goa-form-item label="Year">
    <goa-input width="100px" />
  </goa-form-item>
</goa-block>

[syedszeeshan]

https://github.com/GovAlta/ui-components/pull/2296/files#diff-b8d12a43488867b685920010422ce0c924699a3e5dad8286a3e041612c6f2898

As discussed with Thomas, the PR #2296 will take care of this dropdown issue.