QtActivityBase: Don't finish after library loading fails

Since we show an alert dialog for the user to let them know the loading
failed, and accepting the dialog will finish the Activity, there is no
need to call finish() right after showing the dialog.

Change-Id: I954ba1d0b77591665baf2f1e0eb94567768902db
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
(cherry picked from commit 55fe33f794c1961f2c691b91fe58525dd1a203e0)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/android/jar/src/org/qtproject/qt/android/QtActivityBase.java

@@ -115,12 +115,10 @@ public class QtActivityBase extends Activity
                         loader.getMainLibraryPath());
             } else {
                 showErrorDialog();
-                finish();
             }
         } catch (IllegalArgumentException e) {
             e.printStackTrace();
             showErrorDialog();
-            finish();
         }
     }