fix(polls): Disable submit button if no answers have been chosen

css/_polls.scss

     &:disabled {
         background-color: #00225A;
         color: #858585;
+        cursor: default;
     }
 
     & > *:not(:last-child) {

react/features/polls/components/native/PollAnswer.js

 import { Button } from 'react-native-paper';
 
 import { BUTTON_MODES } from '../../../chat/constants';
+import { isSubmitAnswerDisabled } from '../../functions';
 import AbstractPollAnswer from '../AbstractPollAnswer';
 import type { AbstractProps } from '../AbstractPollAnswer';
 
 
 
 const PollAnswer = (props: AbstractProps) => {
-
     const {
         checkBoxStates,
         poll,
                 </Button>
                 <Button
                     color = '#17a0db'
+                    disabled = { isSubmitAnswerDisabled(checkBoxStates) }
                     mode = { BUTTON_MODES.CONTAINED }
                     onPress = { submitAnswer }
                     style = { chatStyles.pollCreateButton } >

react/features/polls/components/web/PollAnswer.js

 import { Checkbox } from '@atlaskit/checkbox';
 import React from 'react';
 
+import { isSubmitAnswerDisabled } from '../../functions';
 import AbstractPollAnswer from '../AbstractPollAnswer';
 import type { AbstractProps } from '../AbstractPollAnswer';
 
-
 const PollAnswer = (props: AbstractProps) => {
-
     const {
         checkBoxStates,
         poll,
                 </button>
                 <button
                     aria-label = { t('polls.answer.submit') }
-                    className = { 'poll-small-primary-button' }
+                    className = 'poll-small-primary-button'
+                    disabled = { isSubmitAnswerDisabled(checkBoxStates) }
                     onClick = { submitAnswer }>
                     <span>{t('polls.answer.submit')}</span>
                 </button>

react/features/polls/functions.js

 
     return nbUnreadPolls;
 }
+
+/**
+ * Determines if the submit poll answer button should be disabled.
+ *
+ * @param {Array<boolean>} checkBoxStates - The states of the checkboxes.
+ * @returns {boolean}
+ */
+export function isSubmitAnswerDisabled(checkBoxStates: Array<boolean>) {
+    return !checkBoxStates.find(checked => checked);
+}