Adding a CoreStartable object to dump the history of MSDL playback.

The object's purpose is to dump the MSDL library history of the most
recent events.

Test: presubmit.
Test: manual. Ran adb shell dumpsys activity com.anroid.systemui and
  verified the presence of MSDL events
Flag: NONE The usage of the MSDL player is flagged elsewhere.
Bug: 344654090

Change-Id: I52b2e270424c8e063dcdf9bbf38280140bcc1c73