revert back to android support lib

Change from support library to androidx

src/android/BackgroundModeExt.java

@@ -101,9 +101,6 @@ public class BackgroundModeExt extends CordovaPlugin {
             case "webview":
                 disableWebViewOptimizations();
                 break;
-            case "enableWebview":
-                enableWebViewOptimizations();
-                break;
             case "appstart":
                 openAppStart(args.opt(0));
                 break;
@@ -199,31 +196,6 @@ public class BackgroundModeExt extends CordovaPlugin {
         thread.start();
     }
 
-    private void enableWebViewOptimizations() {
-        Thread thread = new Thread(){
-            public void run() {
-                try {
-                    Thread.sleep(1000);
-                    getApp().runOnUiThread(() -> {
-                        View view = webView.getView();
-
-                        try {
-                            Class.forName("org.crosswalk.engine.XWalkCordovaView")
-                                 .getMethod("onHide")
-                                 .invoke(view);
-                        } catch (Exception e){
-                            view.dispatchWindowVisibilityChanged(View.GONE);
-                        }
-                    });
-                } catch (InterruptedException e) {
-                    // do nothing
-                }
-            }
-        };
-
-        thread.start();
-    }
-
     /**
      * Disables battery optimizations for the app.
      * Requires permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS to function.

www/background-mode.js

@@ -164,14 +164,6 @@ exports.disableWebViewOptimizations = function()
     }
 };
 
-exports.enableWebViewOptimizations = function()
-{
-    if (this._isAndroid)
-    {
-        cordova.exec(null, null, 'BackgroundModeExt', 'enableWebview', []);
-    }
-};
-
 /**
  * Disables battery optimazation mode for the app.
  *