Explore: Add setting for default time offset (#90401)

* Add setting for explore for a different time offset

* fix linter

* Add validation for duration value

pkg/api/dtos/frontend_settings.go

@@ -204,6 +204,7 @@ type FrontendSettingsDTO struct {
 	TrustedTypesDefaultPolicyEnabled    bool     `json:"trustedTypesDefaultPolicyEnabled"`
 	CSPReportOnlyEnabled                bool     `json:"cspReportOnlyEnabled"`
 	DisableFrontendSandboxForPlugins    []string `json:"disableFrontendSandboxForPlugins"`
+	ExploreDefaultTimeOffset            string   `json:"exploreDefaultTimeOffset"`
 
 	Auth FrontendSettingsAuthDTO `json:"auth"`
 

pkg/api/frontendsettings.go

@@ -227,6 +227,7 @@ func (hs *HTTPServer) getFrontendSettings(c *contextmodel.ReqContext) (*dtos.Fro
 		RootFolderUID:                       accesscontrol.GeneralFolderUID,
 		LocalFileSystemAvailable:            hs.Cfg.LocalFileSystemAvailable,
 		ReportingStaticContext:              hs.Cfg.ReportingStaticContext,
+		ExploreDefaultTimeOffset:            hs.Cfg.ExploreDefaultTimeOffset,
 
 		BuildInfo: dtos.FrontendSettingsBuildInfoDTO{
 			HideVersion:   hideVersion,