Ensure that MTP is enabled by default

Change-Id: Ibd644509935cde1e52b3d368060fdcb6e16f4a99

twrp.cpp

@@ -270,6 +270,13 @@ int main(int argc, char **argv) {
 	}
 
 	// Read the settings file
+#ifdef TW_HAS_MTP
+	// We unmount partitions sometimes during early boot which may override
+	// the default of MTP being enabled by auto toggling MTP off. This
+	// will force it back to enabled then get overridden by the settings
+	// file, assuming that an entry for tw_mtp_enabled is set.
+	DataManager::SetValue("tw_mtp_enabled", 1);
+#endif
 	DataManager::ReadSettingsFile();
 
 	// Fixup the RTC clock on devices which require it