Add support for Bazel in Gerrit tree build

Change-Id: Ie73f849aa8b20f57ca6f70ac56b091c9a339f555

BUILD

diff --git a/BUILD b/BUILD
new file mode 100644
index 0000000..b94daf1
--- /dev/null
+++ b/BUILD
@@ -0,0 +1,12 @@
+load("//tools/bzl:plugin.bzl", "gerrit_plugin")
+
+gerrit_plugin(
+    name = "branch-network",
+    srcs = glob(["src/main/java/**/*.java"]),
+    resources = glob(["src/main/resources/**/*"]),
+    manifest_entries = [
+        "Gerrit-PluginName: branch-network",
+        "Gerrit-Module: com.googlesource.gerrit.plugins.branchnetwork.GitCommitCacheModule",
+        "Gerrit-HttpModule: com.googlesource.gerrit.plugins.branchnetwork.NetworkGraphModule",
+    ],
+)