Add ISessionCallback#onSessionClosed

Bug: 181984005
Test: m android.hardware.biometrics.fingerprint-update-api
Test: m android.hardware.biometrics.face-update-api
Test: atest VtsHalBiometricsFingerprintTargetTest
Change-Id: I766c3ae0dc9916c376da6432a5545af581dda819
diff --git a/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp b/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
index 4cc8b4a..936fcc6 100644
--- a/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
+++ b/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
@@ -120,6 +120,8 @@
         return ndk::ScopedAStatus::ok();
     }
 
+    ndk::ScopedAStatus onSessionClosed() override { return ndk::ScopedAStatus::ok(); }
+
   private:
     std::promise<SessionCallbackInvocation> invocation_promise_;
 };