Allow soong config variables to be boolean-typed

So that you can use `true` instead of `"true"` in select expressions.

Bug: 323382414
Test: m nothing --no-skip-soong-tests
Change-Id: I950bd8e04f8fab5187ea5075514d476227943f33
diff --git a/android/module.go b/android/module.go
index b438150..9c7410c 100644
--- a/android/module.go
+++ b/android/module.go
@@ -2253,7 +2253,20 @@
 		variable := condition.Arg(1)
 		if n, ok := ctx.Config().productVariables.VendorVars[namespace]; ok {
 			if v, ok := n[variable]; ok {
-				return proptools.ConfigurableValueString(v)
+				ty := ""
+				if namespaces, ok := ctx.Config().productVariables.VendorVarTypes[namespace]; ok {
+					ty = namespaces[variable]
+				}
+				switch ty {
+				case "":
+					// strings are the default, we don't bother writing them to the soong variables json file
+					return proptools.ConfigurableValueString(v)
+				case "bool":
+					return proptools.ConfigurableValueBool(v == "true")
+				default:
+					panic("unhandled soong config variable type: " + ty)
+				}
+
 			}
 		}
 		return proptools.ConfigurableValueUndefined()
diff --git a/android/selects_test.go b/android/selects_test.go
index 3093deb..e2dc403 100644
--- a/android/selects_test.go
+++ b/android/selects_test.go
@@ -25,12 +25,13 @@
 
 func TestSelects(t *testing.T) {
 	testCases := []struct {
-		name          string
-		bp            string
-		provider      selectsTestProvider
-		providers     map[string]selectsTestProvider
-		vendorVars    map[string]map[string]string
-		expectedError string
+		name           string
+		bp             string
+		provider       selectsTestProvider
+		providers      map[string]selectsTestProvider
+		vendorVars     map[string]map[string]string
+		vendorVarTypes map[string]map[string]string
+		expectedError  string
 	}{
 		{
 			name: "basic string list",
@@ -584,6 +585,31 @@
 			},
 		},
 		{
+			name: "Select on boolean soong config variable",
+			bp: `
+			my_module_type {
+				name: "foo",
+				my_string: select(soong_config_variable("my_namespace", "my_variable"), {
+					true: "t",
+					false: "f",
+				}),
+			}
+			`,
+			vendorVars: map[string]map[string]string{
+				"my_namespace": {
+					"my_variable": "true",
+				},
+			},
+			vendorVarTypes: map[string]map[string]string{
+				"my_namespace": {
+					"my_variable": "bool",
+				},
+			},
+			provider: selectsTestProvider{
+				my_string: proptools.StringPtr("t"),
+			},
+		},
+		{
 			name: "Select on boolean false",
 			bp: `
 			my_module_type {
@@ -813,6 +839,7 @@
 				}),
 				FixtureModifyProductVariables(func(variables FixtureProductVariables) {
 					variables.VendorVars = tc.vendorVars
+					variables.VendorVarTypes = tc.vendorVarTypes
 				}),
 			)
 			if tc.expectedError != "" {
diff --git a/android/variable.go b/android/variable.go
index 2cdcd53..a331439 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -399,7 +399,8 @@
 
 	PlatformSepolicyCompatVersions []string `json:",omitempty"`
 
-	VendorVars map[string]map[string]string `json:",omitempty"`
+	VendorVars     map[string]map[string]string `json:",omitempty"`
+	VendorVarTypes map[string]map[string]string `json:",omitempty"`
 
 	Ndk_abis *bool `json:",omitempty"`