Stop framework during vts test

Bug: 390787326
Test: atest VtsHalBiometricsFaceTargetTest
Change-Id: Ic842a341f948f245428a97b6e451603a096b3e4a
diff --git a/biometrics/face/aidl/vts/Android.bp b/biometrics/face/aidl/vts/Android.bp
index e037eac..24bb49d 100644
--- a/biometrics/face/aidl/vts/Android.bp
+++ b/biometrics/face/aidl/vts/Android.bp
@@ -28,4 +28,5 @@
         "general-tests",
         "vts",
     ],
+    disable_framework: true,
 }
diff --git a/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp b/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
index 08ab5d6..686f61e 100644
--- a/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
+++ b/biometrics/face/aidl/vts/VtsHalBiometricsFaceTargetTest.cpp
@@ -186,6 +186,7 @@
 
     void TearDown() override {
         // Close the mSession.
+        ASSERT_NE(mSession, nullptr);
         ASSERT_TRUE(mSession->close().isOk());
 
         // Make sure the mSession is closed.