refactor: update rxjs 6 imports

Author: sis0k0

Diff for: nativescript-angular/http-client/http-utils.ts

@@ -1,7 +1,6 @@
 import { NSFileSystem } from "../file-system/ns-file-system";
 
-import { Observable } from "rxjs/Observable";
-import { Observer } from "rxjs/Observer";
+import { Observable, Observer } from "rxjs";
 import { path } from "tns-core-modules/file-system/file-system";
 
 export type httpResponseFactory<T> = (url: string, body: any, status: number) => T;

Diff for: nativescript-angular/http-client/ns-http-backend.ts

@@ -4,7 +4,7 @@ import {
     XhrFactory, HttpResponse,
     HttpErrorResponse, HttpXhrBackend
 } from "@angular/common/http";
-import { Observable } from "rxjs/Observable";
+import { Observable } from "rxjs";
 
 import { NSFileSystem } from "../file-system/ns-file-system";
 import { isLocalRequest, processLocalFileRequest } from "./http-utils";

Diff for: nativescript-angular/http/ns-http.ts

@@ -9,7 +9,7 @@ import {
     ResponseType,
     Response
 } from "@angular/http";
-import { Observable } from "rxjs/Observable";
+import { Observable } from "rxjs";
 import "rxjs/add/observable/fromPromise";
 
 import { isLocalRequest, processLocalFileRequest } from "../http-client/http-utils";

Diff for: nativescript-angular/router/ns-router-link-active.ts

@@ -3,7 +3,7 @@ import {
     ElementRef, Input, OnChanges, OnDestroy,
     QueryList, Renderer
 } from "@angular/core";
-import { Subscription } from "rxjs/Subscription";
+import { Subscription } from "rxjs";
 
 import { NavigationEnd, Router, UrlTree } from "@angular/router";
 import { containsTree } from "./private-imports/router-url-tree";

Diff for: nativescript-angular/router/page-router-outlet.ts

@@ -17,7 +17,7 @@ import { Frame } from "tns-core-modules/ui/frame";
 import { Page, NavigatedData } from "tns-core-modules/ui/page";
 import { profile } from "tns-core-modules/profiling";
 
-import { BehaviorSubject } from "rxjs/BehaviorSubject";
+import { BehaviorSubject } from "rxjs";
 
 import { DEVICE, PAGE_FACTORY, PageFactory } from "../platform-providers";
 import { routerLog as log } from "../trace";