docs: update http with @publicApi tags (#26595)

PR Close #26595

packages/http/src/backends/browser_xhr.ts

@@ -14,6 +14,7 @@ import {Injectable} from '@angular/core';
  * Take care not to evaluate this in non-browser contexts.
  *
  * @deprecated see https://angular.io/guide/http
+ * @publicApi
  */
 @Injectable()
 export class BrowserXhr {

packages/http/src/backends/jsonp_backend.ts

@@ -24,6 +24,7 @@ const JSONP_ERR_WRONG_METHOD = 'JSONP requests must use GET request method.';
  * Base class for an in-flight JSONP request.
  *
  * @deprecated see https://angular.io/guide/http
+ * @publicApi
  */
 export class JSONPConnection implements Connection {
   // TODO(issue/24571): remove '!'.
@@ -140,6 +141,7 @@ export class JSONPConnection implements Connection {
  * A {@link ConnectionBackend} that uses the JSONP strategy of making requests.
  *
  * @deprecated see https://angular.io/guide/http
+ * @publicApi
  */
 @Injectable()
 export class JSONPBackend extends ConnectionBackend {

packages/http/src/backends/xhr_backend.ts

@@ -29,6 +29,7 @@ const XSSI_PREFIX = /^\)\]\}',?\n/;
  * the {@link MockConnection} may be interacted with in tests.
  *
  * @deprecated see https://angular.io/guide/http
+ * @publicApi
  */
 export class XHRConnection implements Connection {
   request: Request;
@@ -189,6 +190,7 @@ export class XHRConnection implements Connection {
  * details.
  *
  * @deprecated see https://angular.io/guide/http
+ * @publicApi
  */
 export class CookieXSRFStrategy implements XSRFStrategy {
   constructor(
@@ -228,6 +230,7 @@ export class CookieXSRFStrategy implements XSRFStrategy {
  * }
  * ```
  * @deprecated see https://angular.io/guide/http
+ * @publicApi
  */
 @Injectable()
 export class XHRBackend implements ConnectionBackend {