Revert^2 "Conditionally pass kernel version to build.prop"

This reverts commit 29fed1efe8.

Reason for revert: Fixed breakage with aosp/3200730, verified with ABTD

Change-Id: I207abd188636673250eb9a070be95db0b82f39e7

android/build_prop.go

@@ -106,7 +106,12 @@ func (p *buildPropModule) GenerateAndroidBuildActions(ctx ModuleContext) {
 		postProcessCmd.Flag("--allow-dup")
 	}
 	postProcessCmd.FlagWithArg("--sdk-version ", config.PlatformSdkVersion().String())
-	postProcessCmd.FlagWithInput("--kernel-version-file-for-uffd-gc ", PathForOutput(ctx, "dexpreopt/kernel_version_for_uffd_gc.txt"))
+	if ctx.Config().EnableUffdGc() == "default" {
+		postProcessCmd.FlagWithInput("--kernel-version-file-for-uffd-gc ", PathForOutput(ctx, "dexpreopt/kernel_version_for_uffd_gc.txt"))
+	} else {
+		// still need to pass an empty string to kernel-version-file-for-uffd-gc
+		postProcessCmd.FlagWithArg("--kernel-version-file-for-uffd-gc ", `""`)
+	}
 	postProcessCmd.Text(p.outputFilePath.String())
 	postProcessCmd.Flags(p.properties.Block_list)
 

android/config.go

@@ -2085,3 +2085,7 @@ func (c *config) UseDebugArt() bool {
 func (c *config) SystemPropFiles(ctx PathContext) Paths {
 	return PathsForSource(ctx, c.productVariables.SystemPropFiles)
 }
+
+func (c *config) EnableUffdGc() string {
+	return String(c.productVariables.EnableUffdGc)
+}

android/variable.go

@@ -509,6 +509,8 @@ type ProductVariables struct {
 	ArtTargetIncludeDebugBuild *bool `json:",omitempty"`
 
 	SystemPropFiles []string `json:",omitempty"`
+
+	EnableUffdGc *string `json:",omitempty"`
 }
 
 type PartitionQualifiedVariablesType struct {