Specify intermediates dir for sepolicy

Policy intermediates are being placed in a seemingly random
intermediates directories.

Currently:
out/target/product/marlin/obj_arm/SHARED_LIBRARIES/libsoftkeymaster_intermediates

Instead, place intermediates in the sepolicy_intermediates dir.

Test: intermediates now placed in:
out/target/product/marlin/obj/ETC/sepolicy_intermediates
Test: Marlin builds, no change to sepolicy on device.
Bug: 36269118

Change-Id: Ib6e9d9033be4dc8db0cc66cb47d9dc35d38703fe
diff --git a/Android.mk b/Android.mk
index 4b3e000..254acd0 100644
--- a/Android.mk
+++ b/Android.mk
@@ -129,6 +129,8 @@
   my_target_arch := mips
 endif
 
+intermediates := $(TARGET_OUT_INTERMEDIATES)/ETC/sepolicy_intermediates
+
 ##################################
 # reqd_policy_mask - a policy.conf file which contains only the bare minimum
 # policy necessary to use checkpolicy.  This bare-minimum policy needs to be