Template attributes not resolved for upgraded Angular 1 component directive

Question

I have the following Angular 1 directive:

return function(module) {
    module.directive('myButtonUpgrade', myButtonUpgrade);

    function myButtonUpgrade() {
        return {
            restrict: 'E',                
            template: template(),                
            scope: {
                image: '=',
                imageColour: '='
            }
        };

        function template() {
            var html = '<my-button visible="flipVisible"\
                            enabled="enabled"\
                            image="{{::image}}"\
                            image-colour="{{::imageColour}}"\
                       </my-button>';

            return html;
        }
    }

    return myButtonUpgrade;
};

The directive uses "my-button" directive inside its template. The "my-button" directive requires "image" and "image-colour" attribute values to be present before compile its template.

I have got the following Angular 2 component which upgrades Angular 1:

import { Component } from '@angular/core';
import { upgradeAdapter } from '../../../upgrade/index';

var myButtonEx = upgradeAdapter.upgradeNg1Component('myButtonUpgrade');

@Component({
    selector: 'my-button-ex',
    template: '<my-button-ex [image]="refresh"></my-button-ex>',
    directives: [myButtonEx] 
})
export class ButtonExComponent {        
}

As you can see the template sets [image] bindings to "refresh", however that did not resolve when rendering "my-button-ex" Angular 1 directive.

It looks like the upgrade adapter tries to compile HTML syntax first without resolving template arguments:

upgrade_ng1_adapter.ts
compileTemplate(...){
   this.linkFn = compileHtml(this.directive.template);
}

"this.directive.template" - template arguments not resolved!

Any ideas?