feat: app hang capture on Android

src/Sentry.Unity.Android/SentryJava.cs

@@ -145,6 +145,9 @@ public void Init(SentryUnityOptions options)
                 androidOptions.Call("setReportHistoricalAnrs", options.AndroidReportHistoricalAnrs);
                 androidOptions.Call("setAttachAnrThreadDump", options.AndroidAttachAnrThreadDump);
 
+                androidOptions.Call("setEnableAppHangTracking", options.Experimental.EnableNativeAppHangTracking);
+                androidOptions.Call("setAppHangTimeoutIntervalMillis", (long)options.AppHangTimeout.TotalMilliseconds);
+
                 using (var logsOptions = androidOptions.Call<AndroidJavaObject>("getLogs"))
                 {
                     logsOptions.Call("setEnabled", options.EnableLogs);

src/Sentry.Unity.Android/SentryNative.cs

@@ -26,10 +26,20 @@ public static class SentryNative
     /// </summary>
     public static void ReinstallBackend() => ReinstallSentryNativeBackendStrategy();
 
+    /// <summary>
+    /// Records an app-hang heartbeat with sentry-native from the calling thread. The first call
+    /// latches the calling thread as the monitored target, so this must run on the Unity main thread.
+    /// </summary>
+    public static void AppHangHeartbeat() => AppHangHeartbeatStrategy();
+
     // libsentry.io
     [DllImport("sentry")]
     private static extern void sentry_reinstall_backend();
 
+    [DllImport("sentry")]
+    private static extern void sentry_app_hang_heartbeat();
+
     // Testing
     internal static Action ReinstallSentryNativeBackendStrategy = sentry_reinstall_backend;
+    internal static Action AppHangHeartbeatStrategy = sentry_app_hang_heartbeat;
 }

src/Sentry.Unity.Android/SentryNativeAndroid.cs

@@ -110,6 +110,17 @@ public static void Configure(SentryUnityOptions options)
 
         options.NativeSupportCloseCallback = () => Close(options);
 
+        if (options.Experimental.EnableNativeAppHangTracking)
+        {
+            Logger?.LogDebug("Starting the app-hang heartbeat coroutine.");
+            SentryMonoBehaviour.Instance.StartAppHangHeartbeat(SentryNative.AppHangHeartbeat);
+
+            // sentry-native handles app-hang detection on the monitored main thread. Skip the C# ANR
+            // watchdog so a hang isn't reported twice (mirrors the iOS/sentry-cocoa and desktop behavior).
+            Logger?.LogDebug("Disabling the C# ANR watchdog - sentry-native handles app hang detection.");
+            options.DisableAnrIntegration();
+        }
+
         Logger?.LogDebug("Fetching installation ID");
 
         var installationId = SentryJava.GetInstallationId();

src/Sentry.Unity/ExperimentalSentryUnityOptions.cs

@@ -40,9 +40,9 @@ public class ExperimentalSentryUnityOptions
     [field: SerializeField] public LinuxBackend LinuxBackend { get; set; } = LinuxBackend.Breakpad;
 
     /// <summary>
-    /// Enables app hang detection via <c>sentry-native</c> on macOS, Windows, and Linux. Defaults to
+    /// Enables app hang detection via <c>sentry-native</c> on macOS, Windows, Linux, and Android. Defaults to
     /// <c>false</c>. Requires the backend to be switched to <see cref="Sentry.Unity.MacosBackend.Native"/>
-    /// on macOS. <c>sentry-native</c> monitors the main thread and
+    /// on macOS. On Android it is routed through the NDK integration. <c>sentry-native</c> monitors the main thread and
     /// produces an app hang event including a stack trace. When enabled, the C# watchdog is skipped to avoid
     /// duplicate reports. The timeout is taken from <c>AppHangTimeout</c>.
     /// </summary>