Correct handling of Launch Browser command.

1) Stk: Create STK Default Url via System Property

- Create a default url, specific to the STK module that
  can be set via a system property.
- This url will be used when processing a launch browser
  proactive command that contains no url data associated
  with it.

2) Stk: Update Launch Browser If Not Already Launched Behavior

- Since the default browser supports tabs, it will never be considered
  unavailable. Thus, there is no  need to send a terminal
  response with a browser unavailable result code.
- Suppress user confirmation when the browser mode is
  launch if not already launched and the alphaid is null or contains
  no text.

BUG=22637280
Change-Id: I44cc1736da3f962cc5a6d7afd7b7f84d845fdb25
1 file changed