Flow: Grid header row and DatePicker causing error

[nemojmenervirat]

Description of the bug

I've tried to add DatePicker in grid header row, for filtering purposes, but when i did i got error "cannot read property 'input' of undefined" when i've opened app in browser (tested with chrome and edge).
10.0.0 (same happened in rc5)

Minimal reproducible example

Class Person has 3 fields (long id, String name, DateTime created)

Expected behavior

Opening app in browser without errors

Actual behavior

[caalador]

This is a bug with DatePicker that is initialised too early with the locale and gets a undefined for this.$ for vaadin-date-picker.html when getting the input field.

Uncaught TypeError: Cannot read property 'input' of undefined
    at HTMLElement._input (vaadin-date-picker.html:290)
    at HTMLElement.get _inputElement [as _inputElement] (vaadin-date-picker-mixin.html:365)
    at HTMLElement.get _inputValue [as _inputValue] (vaadin-date-picker.html:298)
    at updateFormat (VM2166 datepickerConnector.js:49)
    at Object.datepicker.$connector.setLocale (VM2166 datepickerConnector.js:119)

[gilberto-torrezan]

Fixed via https://github.com/vaadin/vaadin-date-picker-flow/pull/118 (and cherry-picked to the 1.0 branch via https://github.com/vaadin/vaadin-date-picker-flow/issues/119 )