DO NOT MERGE: Switch over to new "time.android.com" NTP pool.

Also add logging to measure success/failure details.

Test: builds, boots, and NTP fix obtained
Bug: 32969463

(cherry picked from commit d3f689bf14)

(cherry picked from commit dda938a698)

Change-Id: I67e4f54f8f2ec69b6522fbbe06ef196b1084f44a

core/java/android/net/EventLogTags.logtags

@@ -0,0 +1,6 @@
+# See system/core/logcat/event.logtags for a description of the format of this file.
+
+option java_package android.net
+
+50080 ntp_success (server|3),(rtt|2),(offset|2)
+50081 ntp_failure (server|3),(msg|3)

core/java/android/net/SntpClient.java

@@ -36,8 +36,7 @@ import java.util.Arrays;
  * }
  * </pre>
  */
-public class SntpClient
-{
+public class SntpClient {
     private static final String TAG = "SntpClient";
     private static final boolean DBG = true;
 
@@ -88,6 +87,7 @@ public class SntpClient
         try {
             address = InetAddress.getByName(host);
         } catch (Exception e) {
+            EventLogTags.writeNtpFailure(host, e.toString());
             if (DBG) Log.d(TAG, "request time failed: " + e);
             return false;
         }
@@ -142,6 +142,7 @@ public class SntpClient
             //             = (transit + skew - transit + skew)/2
             //             = (2 * skew)/2 = skew
             long clockOffset = ((receiveTime - originateTime) + (transmitTime - responseTime))/2;
+            EventLogTags.writeNtpSuccess(address.toString(), roundTripTime, clockOffset);
             if (DBG) {
                 Log.d(TAG, "round trip: " + roundTripTime + "ms, " +
                         "clock offset: " + clockOffset + "ms");
@@ -153,6 +154,7 @@ public class SntpClient
             mNtpTimeReference = responseTicks;
             mRoundTripTime = roundTripTime;
         } catch (Exception e) {
+            EventLogTags.writeNtpFailure(address.toString(), e.toString());
             if (DBG) Log.d(TAG, "request time failed: " + e);
             return false;
         } finally {