Add OWNERS for Rust whitelist.

Splits out the Rust paths whitelist into a separate file
under config/ so that OWNERS can be defined for it.

Bug: 141207129
Test: m -j crosvm.experimental
Change-Id: I5effa6783e5c47560b4b1eae12ad0eb9e9ba96fe
diff --git a/Android.bp b/Android.bp
index 25038c6..89a1711 100644
--- a/Android.bp
+++ b/Android.bp
@@ -334,6 +334,7 @@
     srcs: [
         "rust/config/global.go",
         "rust/config/toolchain.go",
+        "rust/config/whitelist.go",
         "rust/config/x86_linux_host.go",
         "rust/config/x86_64_device.go",
     ],