Normalize java source file paths before running "sort -u".

We rely on "sort -u" to dedupe aidl/logtags generated java files added
by both from $(all_java_sources) and from "find
$(PRIVATE_SOURCE_INTERMEDIATES_DIR) -name '*.java".
But "sort -u" doesn't work if any of the aidl/logtags source file path
has "../" in it.
This change fixes this issue by normalizing the source file paths before
passing them to "sort -u".

Change-Id: I12d2c4e0397bed9f426a1ed9b13608d72d01e0df
diff --git a/core/config.mk b/core/config.mk
index 8863064..ba2e7d5 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -550,6 +550,8 @@
 MD5SUM:=md5sum
 endif
 
+NORMALIZE_PATH := build/tools/normalize_path.py
+
 APICHECK_CLASSPATH := $(HOST_JDK_TOOLS_JAR)
 APICHECK_CLASSPATH := $(APICHECK_CLASSPATH):$(HOST_OUT_JAVA_LIBRARIES)/doclava$(COMMON_JAVA_PACKAGE_SUFFIX)
 APICHECK_CLASSPATH := $(APICHECK_CLASSPATH):$(HOST_OUT_JAVA_LIBRARIES)/jsilver$(COMMON_JAVA_PACKAGE_SUFFIX)