added debug logcat to debug DimService
There was no need for binding to the DimService.
Now anytime the alpha seekbar changes, we put its value
into the extra part of the intent and call startService(intent).
Every call to startService will result in a startOnCommand(intent)
for the service and the our intent will be passed along.
Deleted onSaveInstanceState and onRestoreInstanceState from
MainActivity.
Since we are storing the value of alphaSeekBar in the shared
preferences, there's no need to store them somewhere else.