liblog: remove android_ids and replace with getpwuid

Note: This code makes the assumption that getpwuid is
thread safe, which it is ONLY ON BIONIC. Thus,
if you attempt to use this on a non-target build, you
may get burned. Thus, an ifndef checking on __BIONIC__
is used to produce a build error if you attempt to do
so.

Change-Id: I61038c428b71771edcfc76f18d8fc5cbe349238b
Bug: 27999086
Signed-off-by: William Roberts <william.c.roberts@intel.com>