bug: ion-back-button does not display if wrapped in custom component

[Silvest89]

Bug Report Ionic version: [x] 4.0.0.rc-1

Current behavior: I do see in the element list that the second page in the stack gets an can-go-back class. However the ion-back-button remains invisible (display:none)

Expected behavior: ion-back-button should be visible. As there is a previous page in the stack.

Steps to reproduce: I have a page with a sidepanel menu. Which is a tab page. I navigate to the child page with navigateForward(), I can go back either by swiping back or pressing the tab icon.

Ionic info:

Ionic:

   ionic (Ionic CLI)             : 4.7.0 (/usr/local/lib/node_modules/ionic)
   Ionic Framework               : @ionic/angular 4.0.0-rc.1
   @angular-devkit/build-angular : 0.11.4
   @angular-devkit/schematics    : 7.2.1
   @angular/cli                  : 7.2.1
   @ionic/angular-toolkit        : 1.2.2

Cordova:

   cordova (Cordova CLI) : 8.1.2 ([email protected])
   Cordova Platforms     : android 7.1.4, ios 4.5.5
   Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 2.3.1, (and 24 other plugins)

System:

   ios-deploy : 1.9.4
   NodeJS     : v11.6.0 (/usr/local/Cellar/node/11.6.0/bin/node)
   npm        : 6.5.0
   OS         : macOS Mojave
   Xcode      : Xcode 10.1 Build version 10O45e