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

This reverts commit 29fed1efe85cc07bb4311513e4acc1da73dfb298.

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

Change-Id: I207abd188636673250eb9a070be95db0b82f39e7
diff --git a/android/config.go b/android/config.go
index bb2c38a..40a73d6 100644
--- a/android/config.go
+++ b/android/config.go
@@ -2085,3 +2085,7 @@
 func (c *config) SystemPropFiles(ctx PathContext) Paths {
 	return PathsForSource(ctx, c.productVariables.SystemPropFiles)
 }
+
+func (c *config) EnableUffdGc() string {
+	return String(c.productVariables.EnableUffdGc)
+}