Fix google-explicit-constructor warnings in inputflinger.

* Add explicit keyword to conversion constructors.
Bug: 28341362
Test: build with WITH_TIDY=1

Change-Id: I8259317db74b177b6e62a0aa2ad21aead47f698e
diff --git a/services/inputflinger/InputWindow.h b/services/inputflinger/InputWindow.h
index e243637..feca6cf 100644
--- a/services/inputflinger/InputWindow.h
+++ b/services/inputflinger/InputWindow.h
@@ -196,7 +196,7 @@
     void releaseInfo();
 
 protected:
-    InputWindowHandle(const sp<InputApplicationHandle>& inputApplicationHandle);
+    explicit InputWindowHandle(const sp<InputApplicationHandle>& inputApplicationHandle);
     virtual ~InputWindowHandle();
 
     InputWindowInfo* mInfo;