paper-autocomplete breaking following tests

I have run into a scenario where I am testing the options returned in an paper-autocomplete. If I do not select an option, all the following integration and unit tests fail. I have simplified my code to help illustrate the issue.

Here is the autocomplete from my template.

```EmberScript
{{#paper-autocomplete
triggerClass="cd-autcomplete-selector"
placeholder="Find a location..."
label="Find a location..."
allowClear=true
searchText=(readonly locationSearchText)
onSearchTextChange=(action (mut locationSearchText))
selected=selectedLocation
search=(route-action "search")
searchField="label"
labelPath="label"
loadingMessage="Searching locations..."
noMatchesMessage="We were unable to find that location."
onSelectionChange=(action (mut selectedLocation)) as |location autocomplete|}}
{{paper-autocomplete-highlight searchText=term.searchText flags="i" label=location.label}}
{{else}}
We are unable to find that busienss location!
{{/paper-autocomplete}}
```

Here is my search action:

```javascript
search () {
return [
{ field: 'name', label: 'Marietta' },
{ field: 'name', label: 'Mountville' },
{ field: 'name', label: 'Lancaster' }
]
}
```

Here is my acceptance test:
```javascript
test('autocomplete test', function (assert) {
visit('/autocomplete')

fillIn('.cd-autcomplete-selector input', 'Mar')

andThen(() => {
assert.equal(find('.ember-power-select-option:contains(Marietta)').length, 1, 'Should show Marietta.')
})
})
```

After adding the code 137 tests are failing.

I have found a work around for this issue. Which may help you diagnose this issue. By adding a call to selectChoose to select an option. All tests are fixed and pass again.

```javascript
test('autocomplete test', function (assert) {
visit('/autocomplete')

fillIn('.cd-autcomplete-selector input', 'Mar')

andThen(() => {
assert.equal(find('.ember-power-select-option:contains(Marietta)').length, 1, 'Should show Marietta.')

selectChoose('.cd-autcomplete-selector', '.ember-power-select-option:eq(0)')
})
})
```

Start with the paper-autocomplete example and the acceptance test shown in the issue, then run the focused test and the surrounding suite with and without selectChoose. Trace the autocomplete teardown or state handling that affects later tests; done means the test can leave the autocomplete unselected without causing subsequent unit and integration tests to fail.

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