Add init.environ.rc to installclean

BOOTCLASSPATH needs to be rebuilt when switching between build
targets.

Bug: 13282187

Change-Id: I16816abb4246878a60e1aa8c91b6b38c7339950e
Signed-off-by: Adam Hampson <ahampson@google.com>
diff --git a/core/cleanbuild.mk b/core/cleanbuild.mk
index fa67332..dfdf43d 100644
--- a/core/cleanbuild.mk
+++ b/core/cleanbuild.mk
@@ -196,7 +196,8 @@
 	$(PRODUCT_OUT)/obj/EXECUTABLES/adbd_intermediates \
 	$(PRODUCT_OUT)/obj/EXECUTABLES/init_intermediates \
 	$(PRODUCT_OUT)/obj/ETC/mac_permissions.xml_intermediates \
-	$(PRODUCT_OUT)/obj/ETC/sepolicy_intermediates
+	$(PRODUCT_OUT)/obj/ETC/sepolicy_intermediates \
+	$(PRODUCT_OUT)/obj/ETC/init.environ.rc_intermediates
 
 # The files/dirs to delete during a dataclean, which removes any files
 # in the staging and emulator data partitions.