Add logging override helper

This CL removes compile-time log suppression with a runtim override.
With a runtime override we can custom configure logging with a single
level, not quite as flexible as a boolean per level but should suit
our needs. Compile-time log pruning could be done with proguard if
desired.

Bug: 13737123

Change-Id: I8bdcaca44b4dc5c7eab8ef2f74e5181bcacd2727