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/SensorInterface.h b/services/sensorservice/SensorInterface.h
index dafcf2d..0867dc2 100644
--- a/services/sensorservice/SensorInterface.h
+++ b/services/sensorservice/SensorInterface.h
@@ -47,7 +47,7 @@
 
 class BaseSensor : public SensorInterface {
 public:
-    BaseSensor(const sensor_t& sensor);
+    explicit BaseSensor(const sensor_t& sensor);
     BaseSensor(const sensor_t& sensor, const uint8_t (&uuid)[16]);
 
     // Not all sensors need to support batching.
@@ -74,7 +74,7 @@
 
 class HardwareSensor : public BaseSensor {
 public:
-    HardwareSensor(const sensor_t& sensor);
+    explicit HardwareSensor(const sensor_t& sensor);
     HardwareSensor(const sensor_t& sensor, const uint8_t (&uuid)[16]);
 
     virtual ~HardwareSensor();