Add a way to remove duplicates from Bazel label lists, to e.g. avoid duplicate deps.

Test: Added unit tests, and also resolves bp2build error.
Change-Id: I6e01d9e233ec21dbb244e5682cbeebbc3a1ac0c4
diff --git a/bazel/Android.bp b/bazel/Android.bp
index 117fd46..b7c185a 100644
--- a/bazel/Android.bp
+++ b/bazel/Android.bp
@@ -12,6 +12,7 @@
     ],
     testSrcs: [
         "aquery_test.go",
+        "properties_test.go",
     ],
     pluginFor: [
         "soong_build",