marlin: add sensor test utilities

Only for userdebug and eng builds

Change-Id: I3fdc8d8006b2018654a7dab04429f15e49c1f4c8

diff --git a/device-common.mk b/device-common.mk
index 7b46a49..a40b2bb 100755
--- a/device-common.mk
+++ b/device-common.mk

@@ -115,9 +115,15 @@
 
 # Common sensor packages
 PRODUCT_PACKAGES += \
-    sensortest \
     nanoapp_cmd
 
+# sensor utilities (only for userdebug and eng builds)
+ifneq (,$(filter userdebug eng, $(TARGET_BUILD_VARIANT)))
+PRODUCT_PACKAGES += \
+    nanotool \
+    sensortest
+endif
+
 PRODUCT_COPY_FILES += \
     device/google/marlin/sec_config:system/etc/sec_config