Add a toString() method to Sensor for debugging purposes.

Also made the class final, since it cannot be instantiated
by applications.

Change-Id: I540ad56d19debd99426d37b9b63c163827b4c2fc

Author: Jeff Brown

api/17.txt

@@ -9802,7 +9802,7 @@ package android.hardware {
     method public float getZ();
   }
 
-  public class Sensor {
+  public final class Sensor {
     method public float getMaximumRange();
     method public int getMinDelay();
     method public java.lang.String getName();

api/current.txt

@@ -9847,7 +9847,7 @@ package android.hardware {
     method public float getZ();
   }
 
-  public class Sensor {
+  public final class Sensor {
     method public float getMaximumRange();
     method public int getMinDelay();
     method public java.lang.String getName();

core/java/android/hardware/Sensor.java

@@ -26,7 +26,7 @@
  * @see SensorEvent
  *
  */
-public class Sensor {
+public final class Sensor {
 
     /**
      * A constant describing an accelerometer sensor type. See
@@ -202,4 +202,11 @@ void setRange(float max, float res) {
         mMaxRange = max;
         mResolution = res;
     }
+
+    @Override
+    public String toString() {
+        return "{Sensor name=\"" + mName + "\", vendor=\"" + mVendor + "\", version=" + mVersion
+                + ", type=" + mType + ", maxRange=" + mMaxRange + ", resolution=" + mResolution
+                + ", power=" + mPower + ", minDelay=" + mMinDelay + "}";
+    }
 }