Add bazelbuild-rules_rust and tinyjson to soong_integration_tests

aosp/2709668 registers Bazel repos using these directories so we need to symlink them for soong integration tests to pass.

Test: build/soong/tests/bp2build_bazel_test.sh
Change-Id: I8ee7e5c702bd0bfa24eb3778371f497a67bf815a
diff --git a/tests/lib.sh b/tests/lib.sh
index c0b1514..0766d85 100644
--- a/tests/lib.sh
+++ b/tests/lib.sh
@@ -157,6 +157,8 @@
   symlink_directory external/bazelbuild-rules_cc
   symlink_directory external/bazelbuild-rules_python
   symlink_directory external/bazelbuild-rules_java
+  symlink_directory external/bazelbuild-rules_rust
+  symlink_directory external/rust/crates/tinyjson
 
   symlink_file WORKSPACE
   symlink_file BUILD