[Thread] add missing guava dependency in tests

Change-Id: I383e4a0c78dc3b29fc1aa80d16204166f84ae61b
diff --git a/thread/tests/unit/Android.bp b/thread/tests/unit/Android.bp
index 3a087c7..5863673 100644
--- a/thread/tests/unit/Android.bp
+++ b/thread/tests/unit/Android.bp
@@ -36,6 +36,7 @@
         "ctstestrunner-axt",
         "framework-connectivity-pre-jarjar",
         "framework-connectivity-t-pre-jarjar",
+        "guava",
         "guava-android-testlib",
         "net-tests-utils",
         "truth",