Camera VTS: Close the session at the end of stream configuration validation

Not calling mSession->close means that there will be multiple concurrent
sessions open, which may not be supported by the device.

Bug: 280559094
Test: Ran on cuttlefish
Change-Id: Ie622fabd4d0be2f8442e90d1c781bbf905172270
diff --git a/camera/provider/aidl/vts/VtsAidlHalCameraProvider_TargetTest.cpp b/camera/provider/aidl/vts/VtsAidlHalCameraProvider_TargetTest.cpp
index 622b20b..f8d301f 100644
--- a/camera/provider/aidl/vts/VtsAidlHalCameraProvider_TargetTest.cpp
+++ b/camera/provider/aidl/vts/VtsAidlHalCameraProvider_TargetTest.cpp
@@ -3081,7 +3081,11 @@
             ASSERT_EQ(blobMinDurations.size(), blobStallDurations.size());
         }
 
-        // Validate other aspects of stream configuration metadata...
+        // TODO (b/280887191): Validate other aspects of stream configuration metadata...
+
+        ndk::ScopedAStatus ret = mSession->close();
+        mSession = nullptr;
+        ASSERT_TRUE(ret.isOk());
     }
 }