Adds variables to the analytics_api master config YAML file (#3273)

* Adds DATE_FORMAT and DATETIME_FORMAT to the analytics_api config .yml
* Adds DEFAULT_PAGE_SIZE and MAX_PAGE_SIZE variables to the analytics_api master .yml file. See https://github.com/edx/edx-analytics-data-api/pull/128 for how they're used.
* PR review: fixed page size defaults to match app

playbooks/roles/analytics_api/defaults/main.yml

@@ -62,6 +62,10 @@ ANALYTICS_API_ELASTICSEARCH_CONNECTION_CLASS: !!null
 ANALYTICS_API_ELASTICSEARCH_AWS_ACCESS_KEY_ID: !!null
 ANALYTICS_API_ELASTICSEARCH_AWS_SECRET_ACCESS_KEY: !!null
 ANALYTICS_API_ELASTICSEARCH_CONNECTION_DEFAULT_REGION: 'us-east-1'
+ANALYTICS_API_DATE_FORMAT: '%Y-%m-%d'
+ANALYTICS_API_DATETIME_FORMAT: '%Y-%m-%dT%H%M%S'
+ANALYTICS_API_DEFAULT_PAGE_SIZE: 25
+ANALYTICS_API_MAX_PAGE_SIZE: 100
 
 ANALYTICS_API_SERVICE_CONFIG:
   ANALYTICS_DATABASE: 'reports'
@@ -87,6 +91,10 @@ ANALYTICS_API_SERVICE_CONFIG:
   ELASTICSEARCH_AWS_ACCESS_KEY_ID: '{{ ANALYTICS_API_ELASTICSEARCH_AWS_ACCESS_KEY_ID }}'
   ELASTICSEARCH_AWS_SECRET_ACCESS_KEY: '{{ ANALYTICS_API_ELASTICSEARCH_AWS_SECRET_ACCESS_KEY }}'
   ELASTICSEARCH_CONNECTION_DEFAULT_REGION: '{{ ANALYTICS_API_ELASTICSEARCH_CONNECTION_DEFAULT_REGION }}'
+  DATE_FORMAT: '{{ ANALYTICS_API_DATE_FORMAT }}'
+  DATETIME_FORMAT: '{{ ANALYTICS_API_DATETIME_FORMAT }}'
+  DEFAULT_PAGE_SIZE: '{{ ANALYTICS_API_DEFAULT_PAGE_SIZE }}'
+  MAX_PAGE_SIZE: '{{ ANALYTICS_API_MAX_PAGE_SIZE }}'
 
 ANALYTICS_API_REPOS:
   - PROTOCOL: "{{ COMMON_GIT_PROTOCOL }}"