Add test_mainline_modules option support in mk

Bug: 165425972
Test: Apply aosp/1418212
      atest -b hello_world_test
      Check module-info.json for hello_world_test HelloWorldTests and
HelloWorldHostTest

Change-Id: Ie30a09a54b0ae927ca4d8d1aaba2ac0cdb15233a
diff --git a/core/tasks/module-info.mk b/core/tasks/module-info.mk
index d9aebed..cf32d65 100644
--- a/core/tasks/module-info.mk
+++ b/core/tasks/module-info.mk
@@ -19,6 +19,7 @@
 			'"srcs": [$(foreach w,$(sort $(ALL_MODULES.$(m).SRCS)),"$(w)", )], ' \
 			'"srcjars": [$(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)", )], ' \
 			'},\n' \
 	 ) | sed -e 's/, *\]/]/g' -e 's/, *\}/ }/g' -e '$$s/,$$//' >> $@
 	$(hide) echo '}' >> $@