Fix documentation for Wifi ScanResult.timestamp

Bug: 14997906
Change-Id: Idfcf9ade905c7565cc1d59d15aa4362c1b597b72
diff --git a/wifi/java/android/net/wifi/ScanResult.java b/wifi/java/android/net/wifi/ScanResult.java
index e80a8f4..27c2541 100644
--- a/wifi/java/android/net/wifi/ScanResult.java
+++ b/wifi/java/android/net/wifi/ScanResult.java
@@ -59,7 +59,7 @@
     public int frequency;
 
     /**
-     * Time Synchronization Function (tsf) timestamp in microseconds when
+     * timestamp in microseconds (since boot) when
      * this result was last seen.
      */
     public long timestamp;