docs: update auth providers usage

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

docs/auth/bitbucket/provider.md

@@ -57,7 +57,7 @@ In order to use the Bitbucket provider for sign-in, you must configure it with a
 `signIn.resolver`. See the
 [Sign-In Resolver documentation](../identity-resolver.md) for more details on
 how this is done. Note that for the Bitbucket provider, you'll want to use
-`bitbucket` as the provider ID, and `createBitbucketProvider` for the provider
+`bitbucket` as the provider ID, and `providers.bitbucket.create` for the provider
 factory.
 
 The `@backstage/plugin-auth-backend` plugin also comes with two built-in
@@ -74,16 +74,14 @@ same way, but uses the Bitbucket user ID instead, and matches on the
 The following is an example of how to use one of the built-in resolvers:
 
 ```ts
-import {
-  createBitbucketProvider,
-  bitbucketUsernameSignInResolver,
-} from '@backstage/plugin-auth-backend';
+import { providers } from '@backstage/plugin-auth-backend';
 
 // ...
   providerFactories: {
-    bitbucket: createBitbucketProvider({
+    bitbucket: providers.bitbucket.create({
       signIn: {
-        resolver: bitbucketUsernameSignInResolver,
+        resolver:
+          providers.bitbucket.resolvers.usernameMatchingUserEntityAnnotation(),
       },
     }),
   },

docs/auth/identity-resolver.md

@@ -304,7 +304,7 @@ export default async function createPlugin(
   return await createRouter({
     ...
     providerFactories: {
-      google: createGoogleProvider({
+      google: providers.google.create({
         authHandler: async ({
           fullProfile  // Type: passport.Profile,
           idToken      // Type: (Optional) string,