Set force_granularity: 300 in metrics.yml

It appears that the default metrics.yml needs force_granularity: 300
otherwise cloudkitty-processor will fail to process metrics from
Gnocchi. As this is what at least I (in Debian) ship in packages, it
would be nice to have a working default.

Change-Id: I28b43d6131182252c0576d9323bbcdbfb1dbbd0a
Story: 2008598
Task: 41771

Author: thomasgoirand

etc/cloudkitty/metrics.yml

@@ -14,6 +14,7 @@ metrics:
     extra_args:
       aggregation_method: mean
       resource_type: instance
+      force_granularity: 300
 
   image.size:
     unit: MiB
@@ -40,6 +41,7 @@ metrics:
     extra_args:
       aggregation_method: mean
       resource_type: volume
+      force_granularity: 300
 
   network.outgoing.bytes.rate:
     unit: MB

releasenotes/notes/new-forcegranularity-default-b8aaf7d7823aef3b.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    A new directive ``force_granularity: 300`` was added to the default
+    ``metrics.yml`` file for ``cpu`` and ``volume.size``, to match the defaults
+    of ceilometer and avoid logging errors in ``cloudkitty-processor`` with the
+    default setup.