Clarify default tidy check lists.

* Sort all enabled and disabled checks.
* Disable google-default-arguments for external and vendor projects.

Bug: http://b/27779618
Change-Id: I59e6eaf84fddf54bd89eb71a2189d73b64968057
Test: build with WITH_TIDY=1.

core/clang/tidy.mk

@@ -20,17 +20,24 @@
 # or google-runtime-references.
 DEFAULT_GLOBAL_TIDY_CHECKS := \
   $(subst $(space),, \
-    -*,google*,performance*,misc-macro-parentheses \
-    ,-google-readability*,-google-runtime-references \
+    -*,google* \
+    ,misc-macro-parentheses \
+    ,performance* \
+    ,-google-readability* \
+    ,-google-runtime-references \
   )
 
 # There are too many clang-tidy warnings in external and vendor projects.
 # Enable only some google checks for these projects.
 DEFAULT_EXTERNAL_VENDOR_TIDY_CHECKS := \
   $(subst $(space),, \
-    -*,google*,-google-build-using-namespace \
-    ,-google-readability*,-google-runtime-references \
-    ,-google-explicit-constructor,-google-runtime-int \
+    -*,google* \
+    ,-google-build-using-namespace \
+    ,-google-default-arguments \
+    ,-google-explicit-constructor \
+    ,-google-readability* \
+    ,-google-runtime-int \
+    ,-google-runtime-references \
   )
 
 # Every word in DEFAULT_LOCAL_TIDY_CHECKS list has the following format: