fix: app crash on back press to exit (#534)

Author: harshshinde07

app/src/main/java/io/neurolab/main/NeuroLab.java

@@ -159,7 +159,7 @@ protected void onCreate(Bundle savedInstanceState) {
         intentFilter = new IntentFilter();
         // adding the possible USB intent actions.
         intentFilter.addAction(ACTION_USB_PERMISSION);
-        registerReceiver(broadcastReceiver, intentFilter);
+
         appUpdateManager = AppUpdateManagerFactory.create(getApplicationContext());
         appUpdateInfoTask = appUpdateManager.getAppUpdateInfo();
 
@@ -220,6 +220,7 @@ public void onActivityResult(int requestCode, int resultCode, Intent data) {
     protected void onResume() {
         super.onResume();
 
+        registerReceiver(broadcastReceiver, intentFilter);
         SharedPreferences sharedPreferences =
                 PreferenceManager.getDefaultSharedPreferences(this);
         developerMode = sharedPreferences.getBoolean(DEV_MODE_KEY, false);
@@ -270,7 +271,6 @@ public void onBackPressed() {
         if (drawer.isDrawerOpen(GravityCompat.START)) {
             drawer.closeDrawer(GravityCompat.START);
         } else {
-            unregisterReceiver(broadcastReceiver);
             if (mBackPressed + TIME_INTERVAL > System.currentTimeMillis()) {
                 super.onBackPressed();
                 return;
@@ -418,4 +418,11 @@ public void onClick(View v) {
         }
     }
 
+    @Override
+    protected void onPause() {
+        super.onPause();
+        unregisterReceiver(broadcastReceiver);
+    }
+
+
 }