FPII-1637: Back to Updater home page automatically after lock and unlock screen

Display the last saved fragment instead of a new MainFragment during onResume().

Change-Id: I381f2368b9606770b07e2eb4f170671316efe39e
diff --git a/src/com/fairphone/updater/FairphoneUpdater.java b/src/com/fairphone/updater/FairphoneUpdater.java
index 285afbb..945c5dc 100644
--- a/src/com/fairphone/updater/FairphoneUpdater.java
+++ b/src/com/fairphone/updater/FairphoneUpdater.java
@@ -545,6 +545,10 @@
                 {
                     firstFragment = startGappsInstall();  
                 }
+                else if (getTopFragment() != null)
+                {
+                    firstFragment = getTopFragment();
+                }
                 else
                 {
                     firstFragment = new MainFragment();