Fix google-explicit-constructor warnings in sensorservice.

* Add explicit keyword to conversion constructors,
  or use NOLINT for implicit converters.
Bug: 28341362
Test: build with WITH_TIDY=1

Change-Id: Ie7c4dfcdbd069809e103f0dd008ae2fb4b0502f4
diff --git a/services/sensorservice/vec.h b/services/sensorservice/vec.h
index a142bad..9e5d280 100644
--- a/services/sensorservice/vec.h
+++ b/services/sensorservice/vec.h
@@ -322,12 +322,12 @@
 
     vec() { }
     vec(const vec& rhs)  : base(rhs) { }
-    vec(const base& rhs) : base(rhs) { }
+    vec(const base& rhs) : base(rhs) { }  // NOLINT(implicit)
 
     // -----------------------------------------------------------------------
     // conversion constructors
 
-    vec(pTYPE rhs) {
+    vec(pTYPE rhs) {  // NOLINT(implicit)
         for (size_t i=0 ; i<SIZE ; i++)
             base::operator[](i) = rhs;
     }