Disable auto installclean for AAPT config change

PRODUCT_AAPT_CONFIG and PRODUCT_AAPT_PREF_CONFIG don't affect the
installed file list, they only affect how some files are built. The
changing command line is already noticed by ninja, so we'll only re-run
the necessary commands instead of a full installclean.

Change-Id: Ib918b2edeefc539b7f88cb22a1d751c397973b1d
diff --git a/core/cleanbuild.mk b/core/cleanbuild.mk
index f61e3f7..5179455 100644
--- a/core/cleanbuild.mk
+++ b/core/cleanbuild.mk
@@ -152,16 +152,12 @@
 
 previous_build_config_file := $(PRODUCT_OUT)/previous_build_config.mk
 
-# A change in the list of aapt configs warrants an installclean, too.
-aapt_config_list := $(strip $(PRODUCT_AAPT_CONFIG) $(PRODUCT_AAPT_PREF_CONFIG))
-
 current_build_config := \
-    $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT)-{$(aapt_config_list)}
+    $(TARGET_PRODUCT)-$(TARGET_BUILD_VARIANT)
 current_sanitize_target := $(strip $(SANITIZE_TARGET))
 ifeq (,$(current_sanitize_target))
   current_sanitize_target := false
 endif
-aapt_config_list :=
 force_installclean := false
 force_objclean := false