HACK: work around both android-base/logging.h and ADebug.h defining CHECK

One version of the CHECK_* macros are defined by
android-base/logging.h, and another by ADebug.h.  Eventually
the ADebug.h ones should be replaced with the libbase ones, but
that ripples out into a long dependency chain that needs to link
against libbase.  The redefined macro warnings were hidden by the
use of -isystem to include frameworks/av/include.  Hack around it
for now by undefining the libbase ones if they exist.

Bug: 31751828
Bug: 37782039
Test: m -j checkbuild
Change-Id: Ifabff1c2bc6bac198804c951e98f3fee282cd018
(cherry picked from commit 1b1686db)