Pass --non-updatable-system flag to aapt2 when versionCode is unspecified

This change modifies the flags passed to aapt2 when generating the APKs.
Currently, the version code of the platform sdk version is passed to
aapt2 when the bp module definition does not explicitly specify the
`--version-code` flag in "aaptflags" parameter. This change modifies
such behavior so that the newly introduced `--non-updatable-system` flag
is passed instead of implicitly passing the `--version-code`.

If "versionCode" is explicitly specified in the app manifest, the
`--non-updatable-system` flag is overriden and is a no-op. This way, the
build continues to stay agnostic to the content of the manifest files.

This flag is not passed for build actions of android_test modules, as
test targets do not set `versionCode`.

Test: m nothing --no-skip-soong-tests &&  manually inspect aapt2 build rules
Bug: 311724570
Change-Id: Ie3e50506d90da1d28b8039e29d76859b1927b5e2

java/aar.go

@@ -107,6 +107,10 @@ type aaptProperties struct {
 
 	// Names of aconfig_declarations modules that specify aconfig flags that the module depends on.
 	Flags_packages []string
+
+	// If set, `--non-updatable-system` flag is not passed to aapt2 even when
+	// `--version-code` is not specified in the `aaptFlags` property list or in the manifest.
+	DisableNonUpdatableSystem bool `blueprint:"mutated"`
 }
 
 type aapt struct {
@@ -308,9 +312,9 @@ func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkContext android.SdkConte
 	// This behavior has been copied from Make.
 	linkFlags = append(linkFlags, "--target-sdk-version "+minSdkVersion)
 
-	// Version code
-	if !hasVersionCode {
-		linkFlags = append(linkFlags, "--version-code", ctx.Config().PlatformSdkVersion().String())
+	// Mark non updatable when the module does not specify a version code
+	if !a.aaptProperties.DisableNonUpdatableSystem && !hasVersionCode {
+		linkFlags = append(linkFlags, "--non-updatable-system")
 	}
 
 	if !hasVersionName {

java/app.go

@@ -1452,6 +1452,7 @@ func AndroidTestFactory() android.Module {
 	module.appProperties.AlwaysPackageNativeLibs = true
 	module.Module.dexpreopter.isTest = true
 	module.Module.linter.properties.Lint.Test = proptools.BoolPtr(true)
+	module.aaptProperties.DisableNonUpdatableSystem = true
 
 	module.addHostAndDeviceProperties()
 	module.AddProperties(
@@ -1508,6 +1509,7 @@ func AndroidTestHelperAppFactory() android.Module {
 	module.appProperties.AlwaysPackageNativeLibs = true
 	module.Module.dexpreopter.isTest = true
 	module.Module.linter.properties.Lint.Test = proptools.BoolPtr(true)
+	module.aaptProperties.DisableNonUpdatableSystem = true
 
 	module.addHostAndDeviceProperties()
 	module.AddProperties(

java/app_test.go

@@ -4477,5 +4477,54 @@ func TestAppMinSdkVersionOverride(t *testing.T) {
 		fooOverride.BuildParams.Args["args"],
 		"--minSdkVersion  33",
 	)
-
+}
+
+func TestNonUpdatableSystem(t *testing.T) {
+	ctx := testApp(t, `
+		android_app {
+			name: "foo",
+			srcs: ["a.java"],
+			sdk_version: "current",
+			aaptflags: [
+				"--version-code 1",
+			],
+		}
+		android_app {
+			name: "bar",
+			srcs: ["a.java"],
+			sdk_version: "current",
+		}
+		android_test {
+			name: "baz",
+			srcs: ["a.java"],
+			sdk_version: "current",
+		}
+		android_test_helper_app {
+			name: "baz_helper",
+			srcs: ["a.java"],
+			sdk_version: "current",
+		}
+	`)
+
+	hasNonUpdatableSystemFlag := func(module android.TestingModule) bool {
+		moduleAapt2LinkRule := module.Rule("android/soong/java.aapt2Link")
+		linkFlags := moduleAapt2LinkRule.Args["flags"]
+		return strings.Contains(linkFlags, "--non-updatable-system")
+	}
+
+	foo := ctx.ModuleForTests("foo", "android_common")
+	android.AssertBoolEquals(t, "app should not pass `--non-updatable-flags` when --version-code is specified",
+		false, hasNonUpdatableSystemFlag(foo))
+
+	bar := ctx.ModuleForTests("bar", "android_common")
+	android.AssertBoolEquals(t, "app should pass `--non-updatable-flags` when --version-code is not specified",
+		true, hasNonUpdatableSystemFlag(bar))
+
+	baz := ctx.ModuleForTests("baz", "android_common")
+	android.AssertBoolEquals(t, "test should not pass `--non-updatable-flags` even if --version-code is not specified",
+		false, hasNonUpdatableSystemFlag(baz))
+
+	baz_helper := ctx.ModuleForTests("baz_helper", "android_common")
+	android.AssertBoolEquals(t, "test should not pass `--non-updatable-flags` even if --version-code is not specified",
+		false, hasNonUpdatableSystemFlag(baz_helper))
 }