[fuchsia] Add LogSink to runners_integration_tests' sandbox

Although fuchsia.logger.LogSink is provided when using
run-test-component, it still needs to be in the sandbox.

Also make indentation consistent.

Bug: 1132147
Test: The following no longer appears in the system log when running run_cast_runner_integration_tests with and without --use-run-test-component: `app#sys#fuchsia-pkg://fuchsia.com/cast_runner_integration_tests#meta/cast_runner_integration_tests.cmx` is not allowed to connect to `fuchsia.logger.LogSink` because this service is not present in the component's sandbox.
Change-Id: I67d4205156f1a0bc7eb847159ea417ec776a7832
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2586098
Auto-Submit: David Dorwin <ddorwin@chromium.org>
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Wez <wez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836065}

fuchsia/runners/runners_integration_tests.test-cmx

@@ -25,6 +25,7 @@
     "services": [
       "fuchsia.fonts.Provider",
       "fuchsia.intl.PropertyProvider",
+      "fuchsia.logger.LogSink",
       "fuchsia.memorypressure.Provider",
       "fuchsia.net.interfaces.State",
       "fuchsia.posix.socket.Provider",