Rename @RunnableOnService to something more descriptive

There are currently two categories for unit tests in the Core Beam Java SDK: NeedsRunner and RunnableOnService. These categories are insufficiently descriptive for describing the tests that they categorize.

There are two goals for these tests:

• Demonstrate that a runner conforms with the Beam model and the Capability Matrix. These capabilities are described at Capability Matrix Testing
• Demonstrate that a PTransform, when executed on a PipelineRunner, performs as specified

NeedsRunner tests should either:

• Be converted into a runner-independent test (for example, via use of DoFnTester to test that a DoFn throws on invalid input)
• Be converted into a RunnableOnService test

RunnableOnService tests that explicitly test the capabilities of a Model primitive should be categorized into that specific capability. Existing RunnableOnService tests that test the execution of a PTransform should remain RunnableOnService.