Style changes in `libnativebridge-tests`.

This is a follow-up to
https://android-review.git.corp.google.com/c/platform/art/+/3080063.

Test: atest --host libnativebridge-tests
Test: atest libnativebridge-tests
Bug: 189484095
Flag: TEST_ONLY
Change-Id: I8d30747d8713e9c1d29e08758df7c7d9d68e2846
14 files changed