Updated kbnIndex.indices function to issue for non-UTC users

Updated kbnIndex.indices function to have a configuration option of utc_tz.
    
This option is a bool to determine if the user wishes to use UTC or local time when building a list of possible indexes based on the timestamp pattern on the index. This is extremely important for
users who are implementing solutions that by their nature use local time and not UTC.

Resolves https://github.com/elasticsearch/kibana/issues/1487