Use Rust 1.46.0 prebuilts

Change-Id: I798082bb2bc5a0a40cdf470891aff9d9f0db7a07
diff --git a/rust/config/global.go b/rust/config/global.go
index 97de676..5c50f79 100644
--- a/rust/config/global.go
+++ b/rust/config/global.go
@@ -24,7 +24,7 @@
 var pctx = android.NewPackageContext("android/soong/rust/config")
 
 var (
-	RustDefaultVersion = "1.45.2"
+	RustDefaultVersion = "1.46.0"
 	RustDefaultBase    = "prebuilts/rust/"
 	DefaultEdition     = "2018"
 	Stdlibs            = []string{