Correct the logic for when bill split particpants can be selected

src/components/IOUConfirmationList.js

@@ -57,8 +57,8 @@ const propTypes = {
         phoneNumber: PropTypes.string,
     })).isRequired,
 
-    /** Is this IOU associated with existing report */
-    isIOUAttachedToExistingChatReport: PropTypes.bool.isRequired,
+    /** Can the participants be modified or not */
+    canModifyParticipants: PropTypes.bool,
 
     ...windowDimensionsPropTypes,
 
@@ -91,6 +91,7 @@ const defaultProps = {
     onUpdateComment: null,
     comment: '',
     iouType: CONST.IOU.IOU_TYPE.REQUEST,
+    canModifyParticipants: false,
     ...withCurrentUserPersonalDetailsDefaultProps,
 };
 
@@ -275,7 +276,7 @@ class IOUConfirmationList extends Component {
         const shouldShowSettlementButton = this.props.iouType === CONST.IOU.IOU_TYPE.SEND;
         const shouldDisableButton = selectedParticipants.length === 0;
         const recipient = this.state.participants[0];
-        const canModifyParticipants = !this.props.isIOUAttachedToExistingChatReport && this.props.hasMultipleParticipants;
+        const canModifyParticipants = this.props.canModifyParticipants && this.props.hasMultipleParticipants;
 
         return (
             <OptionsSelector

src/pages/iou/IOUModal.js

@@ -450,7 +450,13 @@ class IOUModal extends Component {
                                                 comment={this.state.comment}
                                                 onUpdateComment={this.updateComment}
                                                 iouType={this.props.iouType}
-                                                isIOUAttachedToExistingChatReport={!_.isEmpty(reportID)}
+
+                                                // The participants can only be modified when the action is initiated from directly within a group chat and not the floating-action-button.
+                                                // This is because when there is a group of people, say they are on a trip, and you have some shared expenses with some of the people,
+                                                // but not all of them (maybe someone skipped out on dinner). Then it's nice to be able to select/deselect people from the group chat bill
+                                                // split rather than forcing the user to create a new group, just for that expense. The reportID is empty, when the action was initiated from
+                                                // the floating-action-button (since it is something that exists outside the context of a report).
+                                                canModifyParticipants={!_.isEmpty(reportID)}
                                             />
                                         </AnimatedStep>
                                     )}

src/pages/iou/steps/IOUConfirmPage.js

@@ -43,14 +43,15 @@ const propTypes = {
     /** IOU type */
     iouType: PropTypes.string,
 
-    /** Is this IOU associated with existing report */
-    isIOUAttachedToExistingChatReport: PropTypes.bool.isRequired,
+    /** Can the participants be modified or not */
+    canModifyParticipants: PropTypes.bool,
 };
 
 const defaultProps = {
     onUpdateComment: null,
     comment: '',
     iouType: CONST.IOU.IOU_TYPE.REQUEST,
+    canModifyParticipants: false,
 };
 
 const IOUConfirmPage = props => (
@@ -63,7 +64,7 @@ const IOUConfirmPage = props => (
         onConfirm={props.onConfirm}
         onSendMoney={props.onSendMoney}
         iouType={props.iouType}
-        isIOUAttachedToExistingChatReport={props.isIOUAttachedToExistingChatReport}
+        canModifyParticipants={props.canModifyParticipants}
     />
 );