Merge "Give an error when trying to build "next" targets" into main

ifeq ($(filter $(_all_release_configs), $(TARGET_RELEASE)),)

    $(error No release config found for TARGET_RELEASE: $(TARGET_RELEASE). Available releases are: $(_all_release_configs))

else

# TODO(b/294161396): Remove this logic

ifeq ($(TARGET_RELEASE),next)

ifndef TESTING_TARGET_RELEASE_NEXT

   $(error "next" releases are not supported yet.  b/294161396)

endif

endif

    # Choose flag files

    # Don't sort this, use it in the order they gave us.

    flag_value_files := $(_all_release_configs.$(TARGET_RELEASE).FILES)