Replace forceCount prop with hideIfDot (#12344)

This replaces the `forceCount` prop on room badge components with
`hideIfDot` which hopefully gives a better idea of what it does,
since forceCount did not really force a count. Also remove the
prop where it was just passing the default value anyway.

src/components/views/rooms/RoomSublist.tsx

@@ -657,7 +657,7 @@ export default class RoomSublist extends React.Component<IProps, IState> {
 
                     const badge = (
                         <NotificationBadge
-                            forceCount={true}
+                            hideIfDot={true}
                             notification={this.notificationState}
                             onClick={this.onBadgeClick}
                             tabIndex={tabIndex}