bug(angular, ios): routerDirection is reversed, when tapping current tab on root page of the tab

# Bug Report

**Ionic version:**

**4.11.1**

**Current behavior:**
If you tap the current tab on the root page of the tab, the page transition **other than the routerLink directive** will reverse routerDirection on iOS.

**Expected behavior:**
No matter how many times you tap the tab, it should become the appropriate routerDirection.

**Steps to reproduce:**
1. enable iOS mode
1. go to `/tabs/tab1` page
1. tap button `Tab One`
1. tap link `navigateByUrl Page1`

https://stackblitz.com/edit/ionic-v4-angular-tabs-mv5vvs


**Other information:**

Is routerDirection rewritten when the current tab is tapped even if page transition does not occur?

https://github.com/ionic-team/ionic/blob/master/core/src/components/tab-button/tab-button.tsx#L92-L96
https://github.com/ionic-team/ionic/blob/master/angular/src/directives/navigation/ion-tabs.ts#L79

**Ionic info:**

```
Ionic:

Ionic CLI : 5.4.1 (/Users/imnskh/.anyenv/envs/nodenv/versions/10.16.0/lib/node_modules/ionic)
Ionic Framework : @ionic/angular 4.11.1
@angular-devkit/build-angular : 0.803.9
@angular-devkit/schematics : 8.3.9
@angular/cli : 8.3.9
@ionic/angular-toolkit : 2.0.0

Cordova:

Cordova CLI : 9.0.0 (cordova-lib@9.0.1)
Cordova Platforms : ios 5.0.1
Cordova Plugins : cordova-plugin-ionic-keyboard 2.2.0, cordova-plugin-ionic-webview 3.1.2, (and 23 other plugins)

Utility:

cordova-res : not installed
native-run : not installed

System:

ios-deploy : 1.9.4
ios-sim : 8.0.2
NodeJS : v10.16.0 (/Users/imnskh/.anyenv/envs/nodenv/versions/10.16.0/bin/node)
npm : 6.12.0
OS : macOS Mojave
Xcode : Xcode 11.1 Build version 11A1027
```