Q:

Android WebView prevent page reload

I have a Phonegap packaged application that opens a PDF Viewer when a button is pressed. I did it with the FileOpener2 plugin.
When I go back to the application from the PDF Viewer, the result differs depending on Android versions.
In Android 4.* the application stays where it should be before leaving the application. However, in Android 2.3.7 the WebView reloads the application, which is the behaviour I don´t expect.
I already tried changing android:launchmode to singleTask or singleInstance with no success.
How can I avoid page reload when I came back to the Phonegap application?
Thanks in advance!
Update 1
I have modified the Cordova or Phonegap class CordovaWebViewClient which extends WebViewClient with:
@Override
public void onLoadResource(WebView view, String url) {
    if (url.equals("file:///android_asset/www/index.html")) {
        if (this.firstLoad) {
            this.firstLoad = false;
        } else {
            view.stopLoading();
        }
    }

However the onLoadResource only gets fired when the application started and not when it resumes from another application.

A:

Answering my own question, setting the following properties to the only Acivity in AndroidManifest solves the problem. However I have to test it because it could have problems that I don't know:
android:launchMode="singleInstance"
android:alwaysRetainTaskState="true"

Cheers!
Update
After testing a bug appeared selection a photo in the Gallery with Phonegap Camera plugin that shows "Selection cancelled".
So after reading https://groups.google.com/forum/#!topic/phonegap/R08vOZNm580 I set:
 android:launchMode="singleTask"
 android:taskAffinity=""
 android:excludeFromRecents="true"

