chore(release/candidate): release 2.7.0 (#6700)

Co-authored-by: George Weale <51099682+GWeale@users.noreply.github.com>

Author: adk-bot

.github/.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-  ".": "2.6.3"
+  ".": "2.7.0"
 }