Environment
Provide version numbers for the following components (information can be retrieved by running tns info in your project folder or by inspecting the package.json of the project):

• CLI: 6.1.0
• Cross-platform modules: 6.1.0
• iOS Runtime: 6.1.0

Describe the bug
When having a ProxyViewContainer as first child of TabContentItem, the app crashes. This is very important for Angular. See playground.

To Reproduce
Playground example:
https://play.nativescript.org/?template=play-ng&id=Aa11Ia

1. Run on iOS.
   Result: There is a crash

ERROR:  uncaughtError Error: onMeasure() did not set the measured dimension by calling setMeasuredDimension() ProxyViewContainer(60)

Expected behavior
Should work