Add product variable SelinuxIgnoreNeverallows for sepolicy

This topic also fix build fail on git_main on seahawk-next-userdebug(b/371922616)

Bug: 350881031
Test: Presubmits
Change-Id: I7dbfadde100d833994f3d0429e358ff10d26fc6e
diff --git a/android/variable.go b/android/variable.go
index 417ba89..248e1e8 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -193,6 +193,9 @@
 			Required               []string
 			Vintf_fragment_modules []string
 		}
+		SelinuxIgnoreNeverallows struct {
+			Required []string
+		}
 	} `android:"arch_variant"`
 }