build: separate dist tools and ota tools

aapt is not needed for a dist build and not available in a pdk dist
build.  Create a new list DISTTOOLS that dist builds depends on,
and change OTATOOLS to be DISTTOOLS plus aapt, which is build by
make otatools.

Change-Id: I9a39020640b0e2cade8073aa14ee2ada9a20d78b
diff --git a/core/Makefile b/core/Makefile
index 449bfb5..05bc057 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -956,15 +956,14 @@
 endif
 
 # -----------------------------------------------------------------
-# host tools needed to build OTA packages
+# host tools needed to build dist and OTA packages
 
-OTATOOLS :=  $(HOST_OUT_EXECUTABLES)/minigzip \
+DISTTOOLS :=  $(HOST_OUT_EXECUTABLES)/minigzip \
 	  $(HOST_OUT_EXECUTABLES)/mkbootfs \
 	  $(HOST_OUT_EXECUTABLES)/mkbootimg \
 	  $(HOST_OUT_EXECUTABLES)/fs_config \
 	  $(HOST_OUT_EXECUTABLES)/mkyaffs2image \
 	  $(HOST_OUT_EXECUTABLES)/zipalign \
-	  $(HOST_OUT_EXECUTABLES)/aapt \
 	  $(HOST_OUT_EXECUTABLES)/bsdiff \
 	  $(HOST_OUT_EXECUTABLES)/imgdiff \
 	  $(HOST_OUT_JAVA_LIBRARIES)/dumpkey.jar \
@@ -972,6 +971,9 @@
 	  $(HOST_OUT_EXECUTABLES)/mkuserimg.sh \
 	  $(HOST_OUT_EXECUTABLES)/make_ext4fs
 
+OTATOOLS := $(DISTTOOLS) \
+	  $(HOST_OUT_EXECUTABLES)/aapt
+
 .PHONY: otatools
 otatools: $(OTATOOLS)
 
@@ -1140,7 +1142,7 @@
 
 $(INTERNAL_OTA_PACKAGE_TARGET): KEY_CERT_PAIR := $(DEFAULT_KEY_CERT_PAIR)
 
-$(INTERNAL_OTA_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) $(OTATOOLS) $(SELINUX_DEPENDS)
+$(INTERNAL_OTA_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) $(DISTTOOLS) $(SELINUX_DEPENDS)
 	@echo "Package OTA: $@"
 	$(hide) ./build/tools/releasetools/ota_from_target_files -v \
 	   -p $(HOST_OUT) \
@@ -1168,7 +1170,7 @@
 $(INTERNAL_UPDATE_PACKAGE_TARGET): extensions := $(TARGET_RELEASETOOLS_EXTENSIONS)
 endif
 
-$(INTERNAL_UPDATE_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) $(OTATOOLS) $(SELINUX_DEPENDS)
+$(INTERNAL_UPDATE_PACKAGE_TARGET): $(BUILT_TARGET_FILES_PACKAGE) $(DISTTOOLS) $(SELINUX_DEPENDS)
 	@echo "Package: $@"
 	$(hide) ./build/tools/releasetools/img_from_target_files -v \
 	   -s $(extensions) \