cabana: bug fixes (#29902)

* fix freq

* fix chart legend alignment issue
old-commit-hash: 0bd9df3193

tools/cabana/chart/chartswidget.cc

@@ -289,6 +289,7 @@ void ChartsWidget::splitChart(ChartView *src_chart) {
     }
     src_chart->updateAxisY();
     src_chart->updateTitle();
+    QTimer::singleShot(0, src_chart, &ChartView::resetChartCache);
   }
 }
 

tools/cabana/streams/abstractstream.h

@@ -30,7 +30,7 @@ struct CanData {
   std::vector<std::array<uint32_t, 8>> bit_change_counts;
   std::vector<int> last_delta;
   std::vector<int> same_delta_counter;
-  double last_freq_update_ts = seconds_since_boot();
+  double last_freq_update_ts = 0;
 };
 
 struct CanEvent {