wish of those help After asking google team about this issue, the said that it's probably some viewport layout settings. Webview has some unfortunate defaults due to legacy issues., Adding webview.getSettings().setLayoutAlgorithm(WebSettings.LayoutAlgorithm.TEXT_AUTOSIZING); fixed the issue.
Android: Downloading in webview not working in oreo, it force closes in Oreo devices
This might help you I don't think there's any event callback that instructs that your app is destroyed, if so, then it will re-alive that app - which is totally negating the idea of killing staled apps. Instead, you can always save your app's state whenever user switches away from your app i.e. save whatever you want in onStop method of your Activity.
Tomcat java.io.IOException: Invalid keystore format when loading keystore via Classloader