Revert^3 "Prevent unspecified values in soong_config_string_variable"

This reverts commit bd86457796442ab7d0e47f0c18b050f2edd734ef.

Reason for revert: More breakages

Change-Id: I9252b62444870d3d16a84254190cefb64e0a4bf3
diff --git a/android/soongconfig/modules.go b/android/soongconfig/modules.go
index 8dd9b89..212b752 100644
--- a/android/soongconfig/modules.go
+++ b/android/soongconfig/modules.go
@@ -639,13 +639,9 @@
 // Extracts an interface from values containing the properties to apply based on config.
 // If config does not match a value with a non-nil property set, the default value will be returned.
 func (s *stringVariable) PropertiesToApply(config SoongConfig, values reflect.Value) (interface{}, error) {
-	configValue := config.String(s.variable)
-	if configValue != "" && !InList(configValue, s.values) {
-		return nil, fmt.Errorf("Soong config property %q must be one of %v, found %q", s.variable, s.values, configValue)
-	}
 	for j, v := range s.values {
 		f := values.Field(j)
-		if configValue == v && !f.Elem().IsNil() {
+		if config.String(s.variable) == v && !f.Elem().IsNil() {
 			return f.Interface(), nil
 		}
 	}
@@ -862,13 +858,3 @@
 }
 
 var emptyInterfaceType = reflect.TypeOf(emptyInterfaceStruct{}).Field(0).Type
-
-// InList checks if the string belongs to the list
-func InList(s string, list []string) bool {
-	for _, s2 := range list {
-		if s2 == s {
-			return true
-		}
-	}
-	return false
-}
diff --git a/android/soongconfig/modules_test.go b/android/soongconfig/modules_test.go
index d5d87ef..a7800e8 100644
--- a/android/soongconfig/modules_test.go
+++ b/android/soongconfig/modules_test.go
@@ -303,10 +303,6 @@
 	Bool_var interface{}
 }
 
-type stringSoongConfigVars struct {
-	String_var interface{}
-}
-
 func Test_PropertiesToApply(t *testing.T) {
 	mt, _ := newModuleType(&ModuleTypeProperties{
 		Module_type:      "foo",
@@ -369,51 +365,6 @@
 	}
 }
 
-func Test_PropertiesToApply_String_Error(t *testing.T) {
-	mt, _ := newModuleType(&ModuleTypeProperties{
-		Module_type:      "foo",
-		Config_namespace: "bar",
-		Variables:        []string{"string_var"},
-		Properties:       []string{"a", "b"},
-	})
-	mt.Variables = append(mt.Variables, &stringVariable{
-		baseVariable: baseVariable{
-			variable: "string_var",
-		},
-		values: []string{"a", "b", "c"},
-	})
-	stringVarPositive := &properties{
-		A: proptools.StringPtr("A"),
-		B: true,
-	}
-	conditionsDefault := &properties{
-		A: proptools.StringPtr("default"),
-		B: false,
-	}
-	actualProps := &struct {
-		Soong_config_variables stringSoongConfigVars
-	}{
-		Soong_config_variables: stringSoongConfigVars{
-			String_var: &boolVarProps{
-				A:                  stringVarPositive.A,
-				B:                  stringVarPositive.B,
-				Conditions_default: conditionsDefault,
-			},
-		},
-	}
-	props := reflect.ValueOf(actualProps)
-
-	_, err := PropertiesToApply(mt, props, Config(map[string]string{
-		"string_var": "x",
-	}))
-	expected := `Soong config property "string_var" must be one of [a b c], found "x"`
-	if err == nil {
-		t.Fatalf("Expected an error, got nil")
-	} else if err.Error() != expected {
-		t.Fatalf("Error message was not correct, expected %q, got %q", expected, err.Error())
-	}
-}
-
 func Test_Bp2BuildSoongConfigDefinitions(t *testing.T) {
 	testCases := []struct {
 		desc     string