Put debug/log code under verbose flag

So they are not invoked when verbose flag is off:
(1) that the compiler will optimize to strip out no-op loops
(2) statements are put into a local function variable so invoked only with ALOGV.

Bug: 189837811
Test: examine logcat
Change-Id: I00ba0433f47586d8356423b8147cf9786f1045b9