[SymForce] Lower BAL filter threshold

See #390 (comment)

Topic: sf-update-bal-threshold
Reviewers: brad,nathan,ryan-b
GitOrigin-RevId: 1388d762b232951332577d7a9f0a0ab59a0f8c08

Author: aaron-skydio

symforce/examples/bundle_adjustment_in_the_large/bundle_adjustment_in_the_large.cc

@@ -43,7 +43,7 @@ Eigen::Vector3d CalculateMedianPosition(const sym::Valuesd& values, int num_came
  * See https://github.com/symforce-org/symforce/issues/387
  */
 void FilterCameraOutliers(std::vector<sym::Factord>& factors, sym::Valuesd& values,
-                          int& num_cameras, double threshold = 100.0) {
+                          int& num_cameras, double threshold = 10.0) {
   std::vector<sym::Pose3d> camera_poses;
   std::vector<sym::Factord> filtered_factors;