Add index mappings to ECL image

Add Jaeger index mappings to ECL image. The image installs these mappings as index templates at container start.

https://issues.jboss.org/browse/TRACING-574 installs mappings as templates at Jaeger startup, however. It is more robust to provide the templates directly in the image and let the image install them.

For instance if ES uses emptyDir storage and the ES container restarts, the jaeger might create an index with an incorrect mapping (the template created by jaeger at startup was deleted at restart). https://issues.jboss.org/browse/TRACING-627?focusedCommentId=13764273&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-13764273

Put mappings to https://github.com/openshift/origin-aggregated-logging/tree/master/elasticsearch/index_templates