Upgrade Prometheus to v2.25 change/Remove deprecated flags

The flag storage.tsdb.retention is deprecated and generates warnings
on startup storage.tsdb.retention.time is the new flag.

storage.tsdb.wal-compression is now set as the default in v2.20
and above and is no longer needed

Change-Id: I66f861a354a3cdde69a712ca5fd8a1d1a1eca60a

prometheus/Chart.yaml

@@ -12,10 +12,10 @@
 
 ---
 apiVersion: v1
-appVersion: v2.12.0
+appVersion: v2.25.0
 description: OpenStack-Helm Prometheus
 name: prometheus
-version: 0.1.5
+version: 0.1.6
 home: https://prometheus.io/
 sources:
   - https://github.com/prometheus/prometheus

prometheus/values.yaml

@@ -19,7 +19,7 @@
 images:
   tags:
     apache_proxy: docker.io/httpd:2.4
-    prometheus: docker.io/prom/prometheus:v2.12.0
+    prometheus: docker.io/prom/prometheus:v2.25.0
     helm_tests: docker.io/openstackhelm/heat:newton-ubuntu_xenial
     dep_check: quay.io/airshipit/kubernetes-entrypoint:v1.0.0
     image_repo_sync: docker.io/docker:17.07.0
@@ -533,7 +533,7 @@ conf:
       query.max_concurrency: 20
       query.timeout: 2m
       storage.tsdb.path: /var/lib/prometheus/data
-      storage.tsdb.retention: 7d
+      storage.tsdb.retention.time: 7d
       # NOTE(srwilkers): These settings default to false, but they are
       # exposed here to allow enabling if desired. Please note the security
       # impacts of enabling these flags. More information regarding the impacts
@@ -544,8 +544,6 @@ conf:
       web.enable_admin_api: false
       # If set to true, allows for http reloads and shutdown of Prometheus
       web.enable_lifecycle: false
-      # Enable WAL file compression
-      storage.tsdb.wal-compression: true
     scrape_configs:
       template: |
         {{- $promHost := tuple "monitoring" "public" . | include "helm-toolkit.endpoints.hostname_fqdn_endpoint_lookup" }}

releasenotes/notes/prometheus.yaml

@@ -6,4 +6,5 @@ prometheus:
   - 0.1.3 Revert "Render Rules as Templates"
   - 0.1.4 Fix spacing inconsistencies with flags
   - 0.1.5 Fix spacing inconsistencies with flags
+  - 0.1.6 Upgrade version to v2.25 fix/remove deprecated flags
 ...