Rename Light HAL default implementation variable.

The Light HAL implements a function getLights that returns a vector
of HwLight objects. This vector is called "lights" in Lights.cpp,
but it is called "types" in Lights.h. Lights.h has been changed to
call the vector "lights".

Test: VtsHalLightTargetTest
Change-Id: I1e567d1454d42e3efc0186cde8340c32e7f3456e
diff --git a/light/aidl/default/Lights.h b/light/aidl/default/Lights.h
index d6d5bf1..cba147f 100644
--- a/light/aidl/default/Lights.h
+++ b/light/aidl/default/Lights.h
@@ -26,7 +26,7 @@
 // Default implementation that reports a few placeholder lights.
 class Lights : public BnLights {
     ndk::ScopedAStatus setLightState(int id, const HwLightState& state) override;
-    ndk::ScopedAStatus getLights(std::vector<HwLight>* types) override;
+    ndk::ScopedAStatus getLights(std::vector<HwLight>* lights) override;
 };
 
 }  // namespace light