trusty: keymint: Statically link Rust deps

Vendor libraries can be linked dynamically now, but until more Rust
components are using it, static is more efficient.

Bug: 292062611
Test: TH
Change-Id: I3708f5fac1ace797b6233811adf3ec71218d5738
diff --git a/trusty/keymint/Android.bp b/trusty/keymint/Android.bp
index c19ebbd..19dcc98 100644
--- a/trusty/keymint/Android.bp
+++ b/trusty/keymint/Android.bp
@@ -35,6 +35,7 @@
         "liblibc",
         "liblog_rust",
     ],
+    prefer_rlib: true,
     required: [
         "android.hardware.hardware_keystore.xml",
     ],