Change validator logs in Gradle to info or debug level

[JakeWharton]

> Task :store:verifySqlDelightMigration
Could not retrieve functions
Could not retrieve functions
Detected circular reference in node at path /tables[item]/indexes[item.sqlite_autoindex_item_1]/columns[item.packageName]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item]/indexes[item.sqlite_autoindex_item_1]/columns[item.className]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item]/primaryKey/columns[item.id]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_content]/primaryKey/columns[item_index_content.docid]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_docsize]/primaryKey/columns[item_index_docsize.docid]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_segdir]/indexes[item_index_segdir.sqlite_autoindex_item_index_segdir_1]/columns[item_index_segdir.level]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_segdir]/indexes[item_index_segdir.sqlite_autoindex_item_index_segdir_1]/columns[item_index_segdir.idx]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_segdir]/primaryKey/columns[item_index_segdir.level]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_segdir]/primaryKey/columns[item_index_segdir.idx]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_segments]/primaryKey/columns[item_index_segments.blockid]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.
Detected circular reference in node at path /tables[item_index_stat]/primaryKey/columns[item_index_stat.id]/index. Going deeper would cause an infinite loop, so I'll stop looking at this instance along the current path.

[JakeWharton]

This comes from java-object-diff using SLF4J to log messages. We need to hook that up to Gradle's logging.