Extend add_soong_config_var to support variable list

$(eval SOONG_CONFIG_$1 :=)

endef

# The add_soong_config_var function adds a soong config variable to

# SOONG_CONFIG_*. The variable and its value are then be available to a

# The add_soong_config_var function adds a a list of soong config variables to

# SOONG_CONFIG_*. The variables and their values are then available to a

# soong_config_module_type in an Android.bp file.

# $1 is the namespace. $2 is the variable name.

# Ex: $(call add_soong_config_var,acme,COOL_FEATURE)

# $1 is the namespace. $2 is the list of variables.

# Ex: $(call add_soong_config_var,acme,COOL_FEATURE_A COOL_FEATURE_B)

define add_soong_config_var

$(eval SOONG_CONFIG_$1 += $2) \

$(eval SOONG_CONFIG_$1_$2 := $($2))

$(foreach v,$2,$(eval SOONG_CONFIG_$1_$v := $($v)))

endef

# The add_soong_config_var_value function defines a make variable and also adds