[V3.4] Set bottom tabs visible affects custom top bar

[blueberry6401]

Issue Description

Set bottom tabs visible affects custom component top bar.

Steps to Reproduce / Code Snippets / Screenshots

Example:

1. I have custom top bar

Navigation.mergeOptions(this, {
    topBar: {
      title: {
        component: {
          name: Screens.ReactTitleView,
          alignment: 'center',
          passProps: {
            text: 'Press Me'
          }
        }
      }
    }
});

2. Hide bottom tabs

Navigation.mergeOptions(this, {
      bottomTabs: {
        visible: false
      }
    })

The top bar component disappear, it will show the default top bar or empty if you're not set.

Environment

• React Native Navigation version: 3.4
• React Native version: 0.61.4
• Platform(s) (iOS, Android, or both?): iOS
• Device info (Simulator/Device? OS version? Debug/Release?): All, iOS 13.2