bazel: Add explicit rules_java dependency

We were actually already using rules_java, but pulled it in only as a
transitive dependency. I'm kind of surprised this worked! Anyway, we
should clean it up.

Change-Id: Ie1645600e2c31c41a0f997ac027e7d74c46ee4ab
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/254134
Reviewed-by: Armando Montanez <amontanez@google.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Docs-Not-Needed: Ted Pudlik <tpudlik@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Commit-Queue: Ted Pudlik <tpudlik@google.com>

MODULE.bazel

@@ -31,6 +31,7 @@ bazel_dep(name = "protobuf", version = "28.2", repo_name = "com_google_protobuf"
 bazel_dep(name = "rules_cc", version = "0.0.10")
 bazel_dep(name = "rules_fuzzing", version = "0.5.2")
 bazel_dep(name = "rules_go", version = "0.49.0", repo_name = "io_bazel_rules_go")
+bazel_dep(name = "rules_java", version = "7.9.0")
 bazel_dep(name = "rules_jvm_external", version = "6.2")
 bazel_dep(name = "rules_libusb", version = "0.1.0-rc1")
 bazel_dep(name = "rules_license", version = "1.0.0")