Fix several small logging issues.

This includes:
1) invert HIDE_STACK_CRAWLS to SHOW_STACK_CRAWLS so it's immediately
clear from the config file that something is enabled (if anything is
true).
2) Merge stack collection code into a method, so we can remove the
repeated code.
3) Remove copying of some constants in AppTransition and just import
them directly.

Change-Id: I3190ee0a5963720ac6285b4f48b2705e84f04ab5