Call clang-tidy with -quiet unless WITH_TIDY is set.

* Default builds calls clang-tidy only if enabled locally.
  In this case, clang-tidy should be quiet.
* If WITH_TIDY is 1 or true, let clang-tidy emit default messages.
* Even with -quiet and all warnings are suppressed,
  clang-tidy emits one line message of the number of suppressed messages.
  This one-liner could be suppressed in future changes.

Bug: 69051430
Test: default build and build with WITH_TIDY=1
Change-Id: I3138ef45fc4372f904787bd1a391e8d88050f0b3

core/binary.mk

@@ -1736,16 +1736,15 @@ ifneq (,$(filter 1 true,$(my_tidy_enabled)))
     ifneq ($(LOCAL_TIDY_CHECKS),)
       my_tidy_checks := $(my_tidy_checks),$(LOCAL_TIDY_CHECKS)
     endif
-    # Set up global default clang-tidy flags, which is none.
-    my_tidy_flags := $(WITH_TIDY_FLAGS)
-    # Use local clang-tidy flags if specified.
-    ifneq ($(LOCAL_TIDY_FLAGS),)
-      my_tidy_flags := $(LOCAL_TIDY_FLAGS)
-    endif
+    my_tidy_flags += $(WITH_TIDY_FLAGS) $(LOCAL_TIDY_FLAGS)
     # If tidy flags are not specified, default to check all header files.
     ifeq ($(my_tidy_flags),)
       my_tidy_flags := $(call default_tidy_header_filter,$(LOCAL_PATH))
     endif
+    # If clang-tidy is not enabled globally, add the -quiet flag.
+    ifeq (,$(filter 1 true,$(WITH_TIDY)))
+      my_tidy_flags += -quiet
+    endif
 
     # We might be using the static analyzer through clang-tidy.
     # https://bugs.llvm.org/show_bug.cgi?id=32914