system/core: preparation to pull back interfaces from android/log.h

Point to log/log.h where necessary, define LOG_TAG where necessary.
Accept that private/android_logger.h is suitable replacement for
log/logger.h and android/log.h.

Correct liblog/README

Effectively a cleanup and controlled select revert of
'system/core: drop or replace log/logger.h' and
'system/core: Replace log/log.h with android/log.h'.

Test: compile
Bug: 30465923
Change-Id: Ic2ad157bad6f5efe2c6af293a73bb753300b17a2
diff --git a/bootstat/event_log_list_builder.cpp b/bootstat/event_log_list_builder.cpp
index a6af13e..ce540a0 100644
--- a/bootstat/event_log_list_builder.cpp
+++ b/bootstat/event_log_list_builder.cpp
@@ -20,7 +20,7 @@
 #include <memory>
 #include <string>
 
-#include <android/log.h>
+#include <log/log.h>
 #include <android-base/logging.h>
 
 namespace {
diff --git a/bootstat/event_log_list_builder_test.cpp b/bootstat/event_log_list_builder_test.cpp
index 8f7f323..25909b0 100644
--- a/bootstat/event_log_list_builder_test.cpp
+++ b/bootstat/event_log_list_builder_test.cpp
@@ -18,9 +18,9 @@
 
 #include <inttypes.h>
 
-#include <android/log.h>
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>
+#include <log/log.h>
 
 using testing::ElementsAreArray;
 
diff --git a/bootstat/histogram_logger.cpp b/bootstat/histogram_logger.cpp
index 3144d8b..4f2386c 100644
--- a/bootstat/histogram_logger.cpp
+++ b/bootstat/histogram_logger.cpp
@@ -19,8 +19,8 @@
 #include <cstdlib>
 #include <memory>
 
-#include <android/log.h>
 #include <android-base/logging.h>
+#include <log/log.h>
 
 #include "event_log_list_builder.h"