fix(autocomplete): incorrect evaluation of available space in viewport

[Azahe]

The available space beneath a wrap included space above viewport. When heights of the body
and viewport did not match (e.g. on mobile) dropdown was displayed on the wrong side.
This change make it so available space is calculated properly.

Fixes #10188

[googlebot]

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[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request), but were unable to find agreements for the commit author(s). If you authored these, maybe you used a different email address in the git commits than was used to sign the CLA (login here to double check)? If these were authored by someone else, then they will need to sign a CLA as well, and confirm that they're okay with these being contributed to Google.

[Azahe]

How about now googlebot? :)

[googlebot]

CLAs look good, thanks!

[googlebot]

CLAs look good, thanks!

[clshortfuse]

@Azahe can you file an issue for this with an example? This is so we can better test the PR.

[Azahe]

@clshortfuse Hey, sorry for late response (christmas) - I made a quick example of what I meant: https://codepen.io/Azahe/pen/ObeGrg (assembled from https://material.angularjs.org/latest/demo/autocomplete)

And issue: #10188