cabana: fix incorrect bit color after seek (#27287)

tools/cabana/streams/abstractstream.cc

@@ -72,6 +72,7 @@ void AbstractStream::updateLastMsgsTo(double sec) {
           m.dat = QByteArray((char *)c.getDat().begin(), c.getDat().size());
           m.colors = QVector<QColor>(m.dat.size(), QColor(0, 0, 0, 0));
           m.last_change_t = QVector<double>(m.dat.size(), m.ts);
+          m.bit_change_counts.resize(m.dat.size());
         } else {
           m.freq = m.count / std::max(1.0, m.ts);
         }

tools/cabana/util.cc

@@ -62,6 +62,7 @@ void ChangeTracker::compute(const QByteArray &dat, double ts, uint32_t freq) {
 void ChangeTracker::clear() {
   prev_dat.clear();
   last_change_t.clear();
+  bit_change_counts.clear();
   colors.clear();
 }