Android: make R.java depend on android/res dir

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@28517 a1c6a512-1295-4272-9138-f99709370657
diff --git a/android/android.make b/android/android.make
index 6701cbb..b28f5c9 100644
--- a/android/android.make
+++ b/android/android.make
@@ -55,9 +55,11 @@
 DIRS		+= $(subst ___,data,$(_DIRS))
 DIRS		+= $(BUILDDIR)/libs/armeabi
 
+RES		:= $(wildcard $(ANDROID_DIR)/res/*/*)
+
 CLEANOBJS += bin gen libs data
 
-$(R_JAVA) $(AP_): $(MANIFEST) $(DIRS)
+$(R_JAVA) $(AP_): $(MANIFEST) $(DIRS) $(RES)
 	$(call PRINTS,AAPT $(subst $(BUILDDIR)/,,$@))$(AAPT) package -f -m \
 		-J $(BUILDDIR)/gen -M $(MANIFEST) -S $(ANDROID_DIR)/res \
 		-I $(ANDROID_PLATFORM)/android.jar -F $(AP_)