remove not used file

public/app/plugins/datasource/stackdriver/angular_wrappers.ts

-import { react2AngularDirective } from 'app/core/utils/react2angular';
-import { QueryEditor } from './components/QueryEditor';
-import { AnnotationQueryEditor } from './components/AnnotationQueryEditor';
-
-//This should be removed when the plugin is fully reactified
-export function registerAngularDirectives() {
-  react2AngularDirective('queryEditor', QueryEditor, [
-    'target',
-    'onQueryChange',
-    'onExecuteQuery',
-    ['events', { watchDepth: 'reference' }],
-    ['datasource', { watchDepth: 'reference' }],
-  ]);
-  react2AngularDirective('annotationQueryEditor', AnnotationQueryEditor, [
-    'target',
-    'onQueryChange',
-    'onExecuteQuery',
-    ['datasource', { watchDepth: 'reference' }],
-  ]);
-}