Hygiene: Output content/format pair for moderateReason

When outputting api keys that contain fully user generated content we have
been outputting a content/format pair so api consumers know how to escape
the content.  Additionally this is required for a follow patch which uses
moderateReason within a preview context, previews always use the
content/format pair when injecting the new content into the templates.

Change-Id: Ia5fda59f29415e954380f1282ebfcf4cb71a6be0
Merge "Hygiene: Output content/format pair for moderateReason"