Add ability to dump events in a timeline view.

Adding new event dump which shows the events for all call, sorted by
time of event.

Test: Manual
Bug: 38450166
Change-Id: I9fd4ce92bdf62ef48d6940f03db1f2388003e9fc
diff --git a/telecomm/java/android/telecom/Log.java b/telecomm/java/android/telecom/Log.java
index 6107895..640c9e1 100644
--- a/telecomm/java/android/telecom/Log.java
+++ b/telecomm/java/android/telecom/Log.java
@@ -269,6 +269,23 @@
     }
 
     /**
+     * Dumps the events in a timeline format.
+     * @param pw The {@link IndentingPrintWriter} to write to.
+     * @hide
+     */
+    public static void dumpEventsTimeline(IndentingPrintWriter pw) {
+        // If the Events logger has not been initialized, then there have been no events logged.
+        // Don't load it now!
+        synchronized (sSingletonSync) {
+            if (sEventManager != null) {
+                getEventManager().dumpEventsTimeline(pw);
+            } else {
+                pw.println("No Historical Events Logged.");
+            }
+        }
+    }
+
+    /**
      * Enable or disable extended telecom logging.
      *
      * @param isExtendedLoggingEnabled {@code true} if extended logging should be enabled,