Add virtual Face HAL

Fixes: 230514750
Test: atest VtsHalBiometricsFaceTargetTest
Test: atest VtsHalBiometricsFingerprintTargetTest
Test: atest android.hardware.biometrics.face.FakeFaceEngineTest
Test: atest android.hardware.biometrics.face.FakeFingerprintEngineTest
Test: See README.md
Test: Verified that face and fingerprint get reset upon authenticating.

Change-Id: I57c1a61bec960e3be28736e6050be662ef412d8c
diff --git a/biometrics/face/aidl/default/Session.h b/biometrics/face/aidl/default/Session.h
index 9db17d2..7ca6a1f 100644
--- a/biometrics/face/aidl/default/Session.h
+++ b/biometrics/face/aidl/default/Session.h
@@ -21,6 +21,10 @@
 #include <aidl/android/hardware/biometrics/face/BnSession.h>
 #include <aidl/android/hardware/biometrics/face/ISessionCallback.h>
 
+#include "FakeFaceEngine.h"
+#include "thread/WorkerThread.h"
+#include "util/CancellationSignal.h"
+
 namespace aidl::android::hardware::biometrics::face {
 
 namespace common = aidl::android::hardware::biometrics::common;
@@ -30,7 +34,7 @@
 
 class Session : public BnSession {
   public:
-    explicit Session(std::shared_ptr<ISessionCallback> cb);
+    explicit Session(std::unique_ptr<FakeFaceEngine> engine, std::shared_ptr<ISessionCallback> cb);
 
     ndk::ScopedAStatus generateChallenge() override;
 
@@ -85,8 +89,11 @@
     ndk::ScopedAStatus onContextChanged(const common::OperationContext& context) override;
 
   private:
-    std::shared_ptr<ISessionCallback> cb_;
+    std::unique_ptr<FakeFaceEngine> mEngine;
+    std::shared_ptr<ISessionCallback> mCb;
     std::mt19937 mRandom;
+    std::unique_ptr<WorkerThread> mThread;
+    std::shared_ptr<CancellationSignal> mCancellationSignal;
 };
 
 }  // namespace aidl::android::hardware::biometrics::face