Add the missing unregisterCallback call

The sensor reading thread continues producing
event and refers to the already destroyed
callback object which causes a crash in
SensorsHidlEnvironmentBase::addEvent.

Bug: 153754380
Test: atest VtsHalSensorsV2_0TargetTest
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: Id7fb72c42dc67f89ceef93d937241e1584b853e7
diff --git a/sensors/common/vts/2_X/VtsHalSensorsV2_XTargetTest.h b/sensors/common/vts/2_X/VtsHalSensorsV2_XTargetTest.h
index 745ab2d..75f2c28 100644
--- a/sensors/common/vts/2_X/VtsHalSensorsV2_XTargetTest.h
+++ b/sensors/common/vts/2_X/VtsHalSensorsV2_XTargetTest.h
@@ -737,6 +737,8 @@
     callback.waitForEvents(sensors, kFiveHundredMs + (5 * maxMinDelay));
     activateAllSensors(false);
 
+    getEnvironment()->unregisterCallback();
+
     for (const SensorInfoType& sensor : sensors) {
         // Skip sensors that did not previously report an event
         if (lastEventTimestampMap.find(sensor.sensorHandle) == lastEventTimestampMap.end()) {