Merge "Add target_board_auto soong config variable" into tm-qpr-dev

$(call soong_config_set,art_module,source_build,$(ART_MODULE_BUILD_FROM_SOURCE))

ifdef TARGET_BOARD_AUTO

  $(call add_soong_config_var_value, ANDROID, target_board_auto, $(TARGET_BOARD_AUTO))

endif

# Ensure that those mainline modules who have individually toggleable prebuilts

# are controlled by the MODULE_BUILD_FROM_SOURCE environment variable by

# default.