This adds a line to the "dumpsys SurfaceFlinger" output that shows
build-time configuration values.
Example:
Build configuration: [sf HAS_CONTEXT_PRIORITY] [libui] \
[libgui USE_FENCE_SYNC]
Bug 7206633
Change-Id: Ibe1856b459d34a4be6ee83a4ebfd2807e6cc68a0