Allow arch-specific `symlink_preferred_arch` properties.

Test: m
Bug: 133864678
Change-Id: Ia6e62156adda2b3a51220552bbe4dab738753674
diff --git a/cc/binary.go b/cc/binary.go
index 8428d7e..941f131 100644
--- a/cc/binary.go
+++ b/cc/binary.go
@@ -36,7 +36,7 @@
 	Prefix_symbols *string
 
 	// if set, install a symlink to the preferred architecture
-	Symlink_preferred_arch *bool
+	Symlink_preferred_arch *bool `android:"arch_variant"`
 
 	// install symlinks to the binary.  Symlink names will have the suffix and the binary
 	// extension (if any) appended