Single quotes (#3511) (#399)

Signed-off-by: Modular Magician <[email protected]>

libraries/google_compute_instance.rb

@@ -176,19 +176,19 @@ def label_value_by_key(label_key)
 
   def metadata_keys
     return [] if !defined?(@metadata) || @metadata.nil?
-    @metadata["items"]&.map { |m| m["key"] }
+    @metadata['items']&.map { |m| m['key'] }
   end
 
   def metadata_values
     return [] if !defined?(@metadata) || @metadata.nil?
-    @metadata["items"]&.map { |m| m["value"] }
+    @metadata['items']&.map { |m| m['value'] }
   end
 
   def metadata_value_by_key(metadata_key)
     return [] if !defined?(@metadata) || @metadata.nil?
     @metadata["items"]&.each do |item|
-      if item["key"] == metadata_key
-        return item["value"]
+      if item['key'] == metadata_key
+        return item['value']
       end
     end
     []