Use SPDX-License-Identifier copyright notices and apply consistently
to source throughout the repo. This covers all modules except
service. That one will be updated in a subsequent commit.
GitHub Actions runs in UTC where the timezone starts with a "+" instead
of our local dev machines (in PT or ET) which start with a "-" in
numeric form. So, we expand the regex to allow for those in
WebSocketRequestLogTest.
Along the way, we change from calling `matches` directly on the strings
to calling it on the `assertThat` to get better test output.
Jon Chambers