Update v2.16.4/v2.15.9 release notes with the project list fix

Include the fix of Issue 10326 on v2.16.4 and align wording
with v2.15.9.

Change-Id: Ia3caa878d394a0b32a7d225fded9c84dfa34f4e9
diff --git a/pages/site/releases/2.15.md b/pages/site/releases/2.15.md
index e9d743f..0c57d61 100644
--- a/pages/site/releases/2.15.md
+++ b/pages/site/releases/2.15.md
@@ -404,7 +404,7 @@
 ### 2.15.9
 
 * [Issue 10326](https://bugs.chromium.org/p/gerrit/issues/detail?id=10326):
-Fix excessive heap usage when listing projects.
+Fix excessive heap and CPU usage when listing projects.
 
 * [Issue 10021](https://bugs.chromium.org/p/gerrit/issues/detail?id=10021):
 Encode and quote project name in download commands.
diff --git a/pages/site/releases/2.16.md b/pages/site/releases/2.16.md
index 35a5058..35ec75e 100644
--- a/pages/site/releases/2.16.md
+++ b/pages/site/releases/2.16.md
@@ -548,9 +548,11 @@
   change. This means that the "Same Topic" tab/section now only shows other
   changes in the same topic, but never the current change.
 
-* Create the `.git/hooks` folder in download commands.
-
 #### Other fixes
+* [Issue 10326](https://bugs.chromium.org/p/gerrit/issues/detail?id=10326):
+Fix excessive heap and CPU usage when listing projects.
+
+* Create the `.git/hooks` folder in download commands.
 
 * Add method to get related changes in the Changes API.