amp-date-picker console errors

### Description

multiple warning in console for date picker extension

```
[amp-date-picker] [object HTMLElement]
The "day-size" attribute is changed from the default value 39. You must specify a new "min-height" `for the .amp-date-picker-resize-bug .DayPicker_transitionContainer element in your AMP CSS.
This is necessary due to a bug in the date-picker library. When the bug is fixed, the amp-date-picker-resize-bug CSS class will be removed. See https://github.com/ampproject/amphtml/issues/13897
```

```
amp-date-picker-0.1.js:2 Deprecation warning: value provided is not in a recognized RFC2822 or ISO format. moment construction falls back to js Date(), which is not reliable across all browsers and versions. Non RFC2822/ISO date formats are discouraged and will be removed in an upcoming major release. Please refer to http://momentjs.com/guides/#/warnings/js-date/ for more info.
Arguments:
[0] _isAMomentObject: true, _isUTC: false, _useUTC: false, _l: undefined, _i: FREQ=WEEKLY;WKST=SU;BYDAY=SA,SU, _f: undefined, _strict: undefined, _locale: [object Object]
Error
at Function.createFromInputFallback (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:262292)
at http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:280389
at http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:280440
at bt (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:280734)
at Dt (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:281111)
at kt (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:281193)
at e.a [as lee] (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:259130)
at t._ee (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:558985)
at http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:558047
at Array.filter ()
```

### Reproduction Steps

build the date-picker extension. open http://localhost:8000/examples/date-picker.amp.html and you will see the warnings

### Relevant Logs

```shell
multiple warning in console for date picker extension

[amp-date-picker] [object HTMLElement]
The "day-size" attribute is changed from the default value 39. You must specify a new "min-height" `for the .amp-date-picker-resize-bug .DayPicker_transitionContainer element in your AMP CSS.
This is necessary due to a bug in the date-picker library. When the bug is fixed, the amp-date-picker-resize-bug CSS class will be removed. See https://github.com/ampproject/amphtml/issues/13897
```

```
amp-date-picker-0.1.js:2 Deprecation warning: value provided is not in a recognized RFC2822 or ISO format. moment construction falls back to js Date(), which is not reliable across all browsers and versions. Non RFC2822/ISO date formats are discouraged and will be removed in an upcoming major release. Please refer to http://momentjs.com/guides/#/warnings/js-date/ for more info.
Arguments:
[0] _isAMomentObject: true, _isUTC: false, _useUTC: false, _l: undefined, _i: FREQ=WEEKLY;WKST=SU;BYDAY=SA,SU, _f: undefined, _strict: undefined, _locale: [object Object]
Error
at Function.createFromInputFallback (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:262292)
at http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:280389
at http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:280440
at bt (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:280734)
at Dt (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:281111)
at kt (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:281193)
at e.a [as lee] (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:259130)
at t._ee (http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:558985)
at http://localhost:8000/dist/v0/amp-date-picker-0.1.js:2:558047
at Array.filter ()
```
```

### Browser(s) Affected

_No response_

### OS(s) Affected

_No response_

### Device(s) Affected

_No response_

### AMP Version Affected

_No response_