Add ABFS (Android Build Filesystem) configuration option to Soong

Change-Id: Ibbe81004adc67b1212d7e619a35f7425bfee0d72
diff --git a/ui/build/sandbox_linux.go b/ui/build/sandbox_linux.go
index edb3b66..5c3fec1 100644
--- a/ui/build/sandbox_linux.go
+++ b/ui/build/sandbox_linux.go
@@ -200,6 +200,9 @@
 		// Only log important warnings / errors
 		"-q",
 	}
+	if c.config.UseABFS() {
+		sandboxArgs = append(sandboxArgs, "-B", "{ABFS_DIR}")
+	}
 
 	// Mount srcDir RW allowlists as Read-Write
 	if len(c.config.sandboxConfig.SrcDirRWAllowlist()) > 0 && !c.config.sandboxConfig.SrcDirIsRO() {