soong: Add product variable DevicePageSizeAgnostic

The product variable DevicePageSizeAgnostic will determine
whether AOSP is kernel page size agnostic or not.

Test: source build/envsetup.sh
      lunch aosp_cf_arm64_phone_pgagnostic
      m
      cat out/soong/build.aosp_cf_arm64_phone_pgagnostic.ninja | grep __BIONIC_NO_PAGE_SIZE_MACRO
Bug: 289419664
Change-Id: I33a1a4f1967d7e78432b7b8d90357d16b2002dcc
diff --git a/android/config.go b/android/config.go
index eb89493..efc977b 100644
--- a/android/config.go
+++ b/android/config.go
@@ -190,6 +190,12 @@
 	return String(c.config.productVariables.DeviceMaxPageSizeSupported)
 }
 
+// PageSizeAgnostic returns true when AOSP is page size agnostic,
+// othersise it returns false.
+func (c Config) PageSizeAgnostic() bool {
+	return Bool(c.config.productVariables.DevicePageSizeAgnostic)
+}
+
 // The release version passed to aconfig, derived from RELEASE_VERSION
 func (c Config) ReleaseVersion() string {
 	return c.config.productVariables.ReleaseVersion