Logging the time that we use for the current events range

It appears that sometimes logcat -d returns events that are earlier than
that time, but we need to be sure.

Example:
ACTION_UP from the previous TAPL method:
https://sponge.corp.google.com/target?show=FAILED&sortBy=STATUS&id=1aceab23-6d2a-4b2d-9630-47a74cafe7b9&target=com.google.android.apps.nexuslauncher.tests

Change-Id: Ib83e1cc01402ef638f8ac8a0862e16c5773b82cd
diff --git a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
index 7154444..0a3462f 100644
--- a/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
+++ b/tests/tapl/com/android/launcher3/tapl/LauncherInstrumentation.java
@@ -1208,6 +1208,7 @@
         mTimeBeforeFirstLogEvent = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS")
                 .format(new Date())
                 .replaceAll(" ", "");
+        log("startRecordingEvents: " + mTimeBeforeFirstLogEvent);
     }
 
     private void stopRecordingEvents() {