Fix/suppress hwui google-explicit-constructor warnings

* Add explicit to conversion constructors/operators
* Use NOLINT or NOLINTNEXTLINE to suppress warnings on intended converters

Bug: 28341362
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,google-explicit-constructor
Change-Id: I8c6ebb99679b0a71251024d70a13f8164e67db5e
diff --git a/libs/hwui/Rect.h b/libs/hwui/Rect.h
index 0715187..320190f 100644
--- a/libs/hwui/Rect.h
+++ b/libs/hwui/Rect.h
@@ -57,15 +57,15 @@
 
     inline Rect(float width, float height) : left(0.0f), top(0.0f), right(width), bottom(height) {}
 
-    inline Rect(const SkIRect& rect)
-            :  // NOLINT, implicit
+    inline Rect(const SkIRect& rect) // NOLINT(google-explicit-constructor)
+            :
             left(rect.fLeft)
             , top(rect.fTop)
             , right(rect.fRight)
             , bottom(rect.fBottom) {}
 
-    inline Rect(const SkRect& rect)
-            :  // NOLINT, implicit
+    inline Rect(const SkRect& rect) // NOLINT(google-explicit-constructor)
+            :
             left(rect.fLeft)
             , top(rect.fTop)
             , right(rect.fRight)