Fix test flake in in LastRunInfoScenario (#1345)

features/fixtures/shared/scenarios/LastRunInfoScenario.swift

@@ -10,6 +10,7 @@ class LastRunInfoScenario: Scenario {
 
     override func startBugsnag() {
         config.launchDurationMillis = 0
+        config.sendLaunchCrashesSynchronously = false
         config.addOnSendError {
             if let lastRunInfo = Bugsnag.lastRunInfo {
                 $0.addMetadata(
@@ -24,9 +25,29 @@ class LastRunInfoScenario: Scenario {
     }
 
     override func run() {
+        // Ensure we don't crash the fixture while the previous run's launch crash is being sent.
+        // Don't rely on synchronous launch crash sending because that will only wait up to 2
+        // seconds, and delivery occasionally takes longer than that on BrowserStack devices.
+        waitForDelivery();
+
         if Bugsnag.lastRunInfo?.consecutiveLaunchCrashes == 3 {
             Bugsnag.markLaunchCompleted()
         }
+
         fatalError("Oh no, the app crashed!")
     }
+
+    func waitForDelivery() {
+        let dir = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
+            .appendingPathComponent("com.bugsnag.Bugsnag")
+            .appendingPathComponent(Bundle.main.bundleIdentifier!)
+            .appendingPathComponent("v1")
+            .appendingPathComponent("KSCrashReports")
+
+        while try! !FileManager.default.contentsOfDirectory(at: dir, includingPropertiesForKeys: nil, options: [])
+                .filter({ $0.lastPathComponent.hasPrefix("CrashReport-") }).isEmpty {
+            NSLog("LastRunInfoScenario: waiting for delivery of crash reports...")
+            Thread.sleep(forTimeInterval: 0.1)
+        }
+    }
 }