OAuth: Feature toggle for access token expiration check and docs (#58179)

* Add feature toggle for access token expiration check

* Add docs for configuring refresh tokens

* Update docs

* Update docs based on review

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>

* Improve documentation

* Change access_type default to Offline

* Update docs/sources/setup-grafana/configure-security/configure-authentication/gitlab/index.md

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>

* Update docs/sources/setup-grafana/configure-security/configure-authentication/google/index.md

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>

* Update pkg/services/featuremgmt/registry.go

Co-authored-by: Eric Leijonmarck <eric.leijonmarck@gmail.com>

* Regenerate toggles

* Update Generic OAuth docs

Co-authored-by: Christopher Moyer <35463610+chri2547@users.noreply.github.com>
Co-authored-by: Eric Leijonmarck <eric.leijonmarck@gmail.com>

pkg/services/featuremgmt/registry.go

@@ -357,6 +357,11 @@ var (
 			State:           FeatureStateAlpha,
 			RequiresDevMode: true,
 		},
+		{
+			Name:        "accessTokenExpirationCheck",
+			Description: "Enable OAuth access_token expiration check and token refresh using the refresh_token",
+			State:       FeatureStateStable,
+		},
 		{
 			Name:        "elasticsearchBackendMigration",
 			Description: "Use Elasticsearch as backend data source",

pkg/services/featuremgmt/toggles_gen.go

@@ -263,6 +263,10 @@ const (
 	// Enable folder nesting
 	FlagNestedFolders = "nestedFolders"
 
+	// FlagAccessTokenExpirationCheck
+	// Enable OAuth access_token expiration check and token refresh using the refresh_token
+	FlagAccessTokenExpirationCheck = "accessTokenExpirationCheck"
+
 	// FlagElasticsearchBackendMigration
 	// Use Elasticsearch as backend data source
 	FlagElasticsearchBackendMigration = "elasticsearchBackendMigration"