chore(ns-support-hmr-ng transformer): support app options variable

[DimitarTachev]

PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the [CLA].
• All existing tests are passing: https://github.com/NativeScript/nativescript-dev-webpack/blob/master/CONTRIBUTING.md#testing-locally-by-running-e2e-tests
• Tests for the changes are included.

What is the current behavior?

A runtime exception is thrown when you bootstrap your Angular app using a variable as App options like:
const appOptions = { bootInExistingPage: true }; platformNativeScriptDynamic(appOptions).bootstrapModule(AppModule);

What is the new behavior?

The case is properly handled and covered by an unit test.