Add ARM32 device Rust toolchain.

Bug: 141207434
Test: build example rust device module.
Change-Id: I2d5b45ba09f386e1c7da7d7cdc58f13f31135863
diff --git a/Android.bp b/Android.bp
index b7f9691..afbae17 100644
--- a/Android.bp
+++ b/Android.bp
@@ -333,6 +333,7 @@
         "soong-cc-config",
     ],
     srcs: [
+        "rust/config/arm_device.go",
         "rust/config/arm64_device.go",
         "rust/config/global.go",
         "rust/config/toolchain.go",