Add unit_test option to module-info.json

Bug: 176096135
Test: atest -m hello_world_test, check module-info.json
Change-Id: Id8bc2eb0d93896afcbe5ce87b0205528615f090e
diff --git a/core/tasks/module-info.mk b/core/tasks/module-info.mk
index cf32d65..4bbfd39 100644
--- a/core/tasks/module-info.mk
+++ b/core/tasks/module-info.mk
@@ -20,6 +20,7 @@
 			'"srcjars": [$(foreach w,$(sort $(ALL_MODULES.$(m).SRCJARS)),"$(w)", )], ' \
 			'"classes_jar": [$(foreach w,$(sort $(ALL_MODULES.$(m).CLASSES_JAR)),"$(w)", )], ' \
 			'"test_mainline_modules": [$(foreach w,$(sort $(ALL_MODULES.$(m).TEST_MAINLINE_MODULES)),"$(w)", )], ' \
+			'"is_unit_test": "$(ALL_MODULES.$(m).IS_UNIT_TEST)", ' \
 			'},\n' \
 	 ) | sed -e 's/, *\]/]/g' -e 's/, *\}/ }/g' -e '$$s/,$$//' >> $@
 	$(hide) echo '}' >> $@