Revert "support sandboxed rust rules"

Revert submission 2629131-sandbox-rust-inputs

Reason for revert: Fail on android build.

Reverted changes: /q/submissionid:2629131-sandbox-rust-inputs

Change-Id: Ifd9aa46e80a12d8f4ffa0a2daa74b96727cbb7e6

android/util.go

@@ -33,17 +33,12 @@ func CopyOf[T any](s []T) []T {
 	return append([]T{}, s...)
 }
 
-// Concat returns a new slice concatenated from the input slices. It does not change the input
+// Concat returns a new slice concatenated from the two input slices. It does not change the input
 // slices.
-func Concat[T any](slices ...[]T) []T {
-	newLength := 0
-	for _, s := range slices {
-		newLength += len(s)
-	}
-	res := make([]T, 0, newLength)
-	for _, s := range slices {
-		res = append(res, s...)
-	}
+func Concat[T any](s1, s2 []T) []T {
+	res := make([]T, 0, len(s1)+len(s2))
+	res = append(res, s1...)
+	res = append(res, s2...)
 	return res
 }