Fix typo in rollback reason histogram

The histogram is called "UpgradeDetector", not "UpgradeDetecter".

Bug: None
Change-Id: I06f74a35ead4b17d81eb155b38b6f620f2d42bd4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2440038Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Miriam Polzer <mpolzer@google.com>
Cr-Commit-Position: refs/heads/master@{#812604}

chrome/browser/upgrade_detector/installed_version_updater_chromeos.cc

@@ -53,7 +53,7 @@ void InstalledVersionUpdater::UpdateStatusChanged(
     if (status.is_enterprise_rollback()) {
       update_type = BuildState::UpdateType::kEnterpriseRollback;
 
-      base::UmaHistogramEnumeration("UpgradeDetecter.RollbackReason",
+      base::UmaHistogramEnumeration("UpgradeDetector.RollbackReason",
                                     RollbackReason::kEnterpriseRollback);
 
       LOG(WARNING) << "Device is rolling back, will require powerwash. Reason:"
@@ -63,7 +63,7 @@ void InstalledVersionUpdater::UpdateStatusChanged(
       // Powerwash must have been triggered by channel change.
       update_type = BuildState::UpdateType::kChannelSwitchRollback;
 
-      base::UmaHistogramEnumeration("UpgradeDetecter.RollbackReason",
+      base::UmaHistogramEnumeration("UpgradeDetector.RollbackReason",
                                     RollbackReason::kToMoreStableChannel);
 
       LOG(WARNING) << "Device is rolling back, will require powerwash. Reason:"