Unit tests: Compile only on 'eng' builds.

Bug: 26967770
Change-Id: I93e6a108803a62383c2e1b71879196e2b47c38ba
diff --git a/Android.mk b/Android.mk
index 013ee3b..2e54ec2 100644
--- a/Android.mk
+++ b/Android.mk
@@ -122,7 +122,7 @@
 include $(CLEAR_VARS)
 LOCAL_MODULE := libminijail_unittest
 ifdef BRILLO
-  LOCAL_MODULE_TAGS := debug
+  LOCAL_MODULE_TAGS := eng
 endif
 
 LOCAL_CFLAGS := $(minijailCommonCFlags)
@@ -146,7 +146,7 @@
 include $(CLEAR_VARS)
 LOCAL_MODULE := syscall_filter_unittest
 ifdef BRILLO
-  LOCAL_MODULE_TAGS := debug
+  LOCAL_MODULE_TAGS := eng
 endif
 
 LOCAL_CFLAGS := $(minijailCommonCFlags)