disable build since it breaks master

andriod code should not incldue nanohub includes directly like this

device/google/contexthub/util/nanotool/../../firmware/inc/sensors.h:23:10: fatal error: 'plat/inc/taggedPtr.h' file not found
        ^
1 error generated.

Change-Id: If089e5c673379445eeea21c47c769dbc7e8b55c9
diff --git a/util/nanotool/Android.mk b/util/nanotool/Android.mk.disabled
similarity index 100%
rename from util/nanotool/Android.mk
rename to util/nanotool/Android.mk.disabled