feat(gatsby-plugin-google-analytics): Added cookie storage option (#25831)

Author: Oliweer

packages/gatsby-plugin-google-analytics/README.md

@@ -144,6 +144,7 @@ This plugin supports all optional Create Only Fields documented in [Google Analy
 - `legacyCookieDomain`: string
 - `legacyHistoryImport`: boolean
 - `allowLinker`: boolean
+- `storage`: string
 
 This plugin also supports several optional General fields documented in [Google Analytics](https://developers.google.com/analytics/devguides/collection/analyticsjs/field-reference#general):
 

packages/gatsby-plugin-google-analytics/src/gatsby-ssr.js

@@ -13,6 +13,7 @@ const knownOptions = {
     legacyCookieDomain: `string`,
     legacyHistoryImport: `boolean`,
     allowLinker: `boolean`,
+    storage: `string`,
   },
   general: {
     allowAdFeatures: `boolean`,