Add default ctor/dtor to SystemRoutineController

Adds an implementation for the ctor/dtor.

Bug: 1128204
Change-Id: Id5f1534333909d88c44c988258df1007adb3f285
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2503195
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Auto-Submit: Bailey Berro <baileyberro@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821339}

chromeos/components/diagnostics_ui/backend/system_routine_controller.cc

@@ -10,6 +10,9 @@
 namespace chromeos {
 namespace diagnostics {
 
+SystemRoutineController::SystemRoutineController() = default;
+SystemRoutineController::~SystemRoutineController() = default;
+
 void SystemRoutineController::BindCrosHealthdDiagnosticsServiceIfNeccessary() {
   if (!diagnostics_service_ || !diagnostics_service_.is_connected()) {
     cros_healthd::ServiceConnection::GetInstance()->GetDiagnosticsService(