Update 2.14 & 2.15 release notes to include Java 8 requirement

Bug: Issue 7843
Change-Id: I7778e7b855a6519811f47c122555b062334850d3
diff --git a/pages/site/releases/2.14.md b/pages/site/releases/2.14.md
index 9351180..f6ba5d0 100644
--- a/pages/site/releases/2.14.md
+++ b/pages/site/releases/2.14.md
@@ -67,7 +67,9 @@
 ### Java 8
 
 Gerrit now requires Java Runtime Environment (JRE) version 8. It is no longer
-possible to run Gerrit on JRE 7.
+possible to run Gerrit on JRE 7 and it is not compatible with JRE 9 or newer
+yet. For more information, see
+[Issue 7843](https://bugs.chromium.org/p/gerrit/issues/detail?id=7843).
 
 ### Bouncy Castle Libraries
 
diff --git a/pages/site/releases/2.15.md b/pages/site/releases/2.15.md
index 8f57d8a..7d1882c 100644
--- a/pages/site/releases/2.15.md
+++ b/pages/site/releases/2.15.md
@@ -166,6 +166,12 @@
 to allow the new strict functionality to be optionally enabled. By default it is
 disabled to maintain backwards compatibility with previous release.
 
+### Java runtime version requirement
+
+Gerrit requires Java Runtime Environment (JRE) version 8; it is not compatible
+with JRE 9 or newer yet. For more information, see
+[Issue 7843](https://bugs.chromium.org/p/gerrit/issues/detail?id=7843).
+
 ## New Features
 
 ### PolyGerrit UI