It;s not printing webview because google app u r using in that webview debugger is not enabled so u r not allowed to work on webview elements…
as suggested in above comments just check if the element u want to click comes under native context using UIAutomatorviewer
I also suggest if u want to use gmail then open gmail.com in browser using appium and then perform this step as gmail is a third party app u cannot change anything in it’s build process so you can use appium automation on it as a hybrid app … But if you launch it as a webApp I hope you can interact with its elements …