ReleaseNotes: Updated changelog and release notes for 8.1.5 (#39464)

Co-authored-by: Marcus Efraimsson <marcus.efraimsson@gmail.com>

CHANGELOG.md

@@ -84,6 +84,16 @@ Panel queries and/or annotation queries that used more than one statistic will b
 
 <!-- 8.2.0-beta1 END -->
 
+<!-- 8.1.5 START -->
+
+# 8.1.5 (2021-09-21)
+
+### Bug fixes
+
+- **BarChart:** Fixes panel error that happens on second refresh. [#39304](https://github.com/grafana/grafana/pull/39304), [@DanCech](https://github.com/DanCech)
+
+<!-- 8.1.5 END -->
+
 <!-- 8.1.4 START -->
 
 # 8.1.4 (2021-09-16)

docs/sources/release-notes/_index.md

@@ -9,6 +9,7 @@ Here you can find detailed release notes that list everything that is included i
 about deprecations, breaking changes as well as changes that relate to plugin development.
 
 - [Release notes for 8.2.0-beta1]({{< relref "release-notes-8-2-0-beta1" >}})
+- [Release notes for 8.1.5]({{< relref "release-notes-8-1-5" >}})
 - [Release notes for 8.1.4]({{< relref "release-notes-8-1-4" >}})
 - [Release notes for 8.1.3]({{< relref "release-notes-8-1-3" >}})
 - [Release notes for 8.1.2]({{< relref "release-notes-8-1-2" >}})

docs/sources/release-notes/release-notes-8-1-5.md

@@ -0,0 +1,14 @@
++++
+title = "Release notes for Grafana 8.1.5"
+[_build]
+list = false
++++
+
+<!-- Auto generated by update changelog github action -->
+
+# Release notes for Grafana 8.1.5
+
+### Bug fixes
+
+- **BarChart:** Fixes panel error that happens on second refresh. [#39304](https://github.com/grafana/grafana/pull/39304), [@DanCech](https://github.com/DanCech)
+