MAINTAINERS.md: Add Kannan (#11057)

- [kannanjgithub](https://github.com/kannanjgithub), Google LLC

Author: sergiitk

MAINTAINERS.md

@@ -10,6 +10,7 @@ for general contribution guidelines.
 ## Maintainers (in alphabetical order)
 - [ejona86](https://github.com/ejona86), Google LLC
 - [jdcormie](https://github.com/jdcormie), Google LLC
+- [kannanjgithub](https://github.com/kannanjgithub), Google LLC
 - [larry-safran](https://github.com/larry-safran), Google LLC
 - [markb74](https://github.com/markb74), Google LLC
 - [ran-su](https://github.com/ran-su), Google LLC