* stable-2.15:
Elasticsearch: Exclude types from V7 which deprecates them
Send an email notification when the HTTP password is deleted or changed
Send email notification when SSH key or GPG key is removed
Show progress on number of users migrated during schema migration 146
Additional changes done in this merge to adjust to stable-2.16:
- Replace slf4j with Flogger.
- Edit newly added soy templates to remove 'autoescape' and 'kind' parameters
which are no longer needed and cause parsing errors.
- Move newly added email sender classes to correct package.
Change-Id: I01a804f10c7247d18a0958eb7e0f03cbcf7453c7
b55aadc48b