google sign in plist fix (#80)

* chore: google sign in plist fix

* chore: format with prettier

Author: BieganM

plugin/src/withPlist.ts

@@ -3,7 +3,16 @@ import { ConfigPlugin, withInfoPlist } from '@expo/config-plugins'
 const withPlist: ConfigPlugin = (expoConfig) =>
   withInfoPlist(expoConfig, (plistConfig) => {
     const scheme = typeof expoConfig.scheme === 'string' ? expoConfig.scheme : expoConfig.ios?.bundleIdentifier
-    if (scheme) plistConfig.modResults.CFBundleURLTypes = [{ CFBundleURLSchemes: [scheme] }]
+
+    if (scheme) {
+      const existingURLTypes = plistConfig.modResults.CFBundleURLTypes || []
+      const schemeExists = existingURLTypes.some((urlType: any) => urlType.CFBundleURLSchemes?.includes(scheme))
+
+      if (!schemeExists) {
+        plistConfig.modResults.CFBundleURLTypes = [...existingURLTypes, { CFBundleURLSchemes: [scheme] }]
+      }
+    }
+
     return plistConfig
   })