Fix google-explicit-constructor warnings in frameworks/base

* Add explicit keyword to conversion constructors.
* Add NOLINT to implicit conversion constructors.

Bug: 28341362
Test: build with clang-tidy
Change-Id: Ie4d37072ab57d1662d18db4de1c8577247f43337
diff --git a/libs/hwui/thread/Future.h b/libs/hwui/thread/Future.h
index a3ff3bc..177eebd 100644
--- a/libs/hwui/thread/Future.h
+++ b/libs/hwui/thread/Future.h
@@ -27,7 +27,7 @@
 template<typename T>
 class Future: public LightRefBase<Future<T> > {
 public:
-    Future(Condition::WakeUpType type = Condition::WAKE_UP_ONE): mBarrier(type), mResult() { }
+    explicit Future(Condition::WakeUpType type = Condition::WAKE_UP_ONE): mBarrier(type), mResult() { }
     ~Future() { }
 
     /**