libaudiohal: Call IDevice.close in HAL V6

Call IDevice.close when the client doesn't need the device.

Bug: 114451103
Test: adb shell stop
Change-Id: I486db716be59cd4ea0f6d75d0e366f802ee9b06d
Merged-In: I486db716be59cd4ea0f6d75d0e366f802ee9b06d

media/libaudiohal/impl/DeviceHalHidl.cpp

@@ -100,8 +100,12 @@ DeviceHalHidl::DeviceHalHidl(const sp<IDevice>& device)
 
 DeviceHalHidl::~DeviceHalHidl() {
     if (mDevice != 0) {
+#if MAJOR_VERSION <= 5
         mDevice.clear();
         hardware::IPCThreadState::self()->flushCommands();
+#elif MAJOR_VERSION >= 6
+        mDevice->close();
+#endif
     }
 }