Verify mPollThread is joinable before detaching am: 65945cfb15 am: f75cf1cf4d
am: ce98cb7938

Change-Id: If939dfc29dade2ab90dc398253e5eb73752e4c19
diff --git a/sensors/common/vts/utils/SensorsHidlEnvironmentBase.cpp b/sensors/common/vts/utils/SensorsHidlEnvironmentBase.cpp
index affdf8b..fa0e2e9 100644
--- a/sensors/common/vts/utils/SensorsHidlEnvironmentBase.cpp
+++ b/sensors/common/vts/utils/SensorsHidlEnvironmentBase.cpp
@@ -29,7 +29,9 @@
 
 void SensorsHidlEnvironmentBase::HidlTearDown() {
     mStopThread = true;
-    mPollThread.detach();
+    if (mPollThread.joinable()) {
+        mPollThread.detach();
+    }
 }
 
 void SensorsHidlEnvironmentBase::catEvents(std::vector<Event>* output) {