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/RecentEventLogger.h b/services/sensorservice/RecentEventLogger.h
index 4f9bc4a..973a247 100644
--- a/services/sensorservice/RecentEventLogger.h
+++ b/services/sensorservice/RecentEventLogger.h
@@ -35,7 +35,7 @@
 // behavior.
 class RecentEventLogger : public Dumpable {
 public:
-    RecentEventLogger(int sensorType);
+    explicit RecentEventLogger(int sensorType);
     void addEvent(const sensors_event_t& event);
     bool populateLastEvent(sensors_event_t *event) const;
     bool isEmpty() const;
@@ -46,7 +46,7 @@
 
 protected:
     struct SensorEventLog {
-        SensorEventLog(const sensors_event_t& e);
+        explicit SensorEventLog(const sensors_event_t& e);
         timespec mWallTime;
         sensors_event_t mEvent;
     };