Update .release-please-manifest.json

Author: sofisl

.release-please-manifest.json

@@ -1,5 +1,6 @@
 {
   "gax": "4.6.0",
   "tools": "0.4.6",
-  "logging-utils": "1.0.1"
+  "logging-utils": "1.0.1",
+  "separate-pull-requests": true,
 }