Revert "MainActivity: remove automatic retry logic"

This reverts commit 1ebb117.

app/src/main/java/fr/free/nrw/commons/contributions/MainActivity.java

@@ -365,6 +365,21 @@ public boolean onOptionsItemSelected(MenuItem item) {
         }
     }
 
+    /**
+     * Retry all failed uploads as soon as the user returns to the app
+     */
+    @SuppressLint("CheckResult")
+    private void retryAllFailedUploads() {
+        contributionDao.
+            getContribution(Collections.singletonList(Contribution.STATE_FAILED))
+            .subscribeOn(Schedulers.io())
+            .subscribe(failedUploads -> {
+                for (Contribution contribution: failedUploads) {
+                    contributionsFragment.retryUpload(contribution);
+                }
+            });
+    }
+
     public void toggleLimitedConnectionMode() {
         defaultKvStore.putBoolean(CommonsApplication.IS_LIMITED_CONNECTION_MODE_ENABLED,
             !defaultKvStore
@@ -411,6 +426,7 @@ protected void onResume() {
             WelcomeActivity.startYourself(this);
         }
 
+        retryAllFailedUploads();
     }
 
     @Override