[content-service] Remove not-working test run from leeway build (dead code)

The unit test leeway build is not executed (dead code) and does not work. This commit adds `dontTest: false` to the lib build instead.

Author: corneliusludmann

components/content-service/BUILD.yaml

@@ -12,9 +12,4 @@ packages:
       - "**"
     config:
       packaging: library
-  - name: test
-    type: docker
-    deps:
-    # - :app
-    config:
-      dockerfile: Dockerfile.unittest
+      dontTest: false