Build test server on ubuntu 18

[bergundy]

Use buildjet-2vcpu-ubuntu-1804 to build the test server.
GitHub deprecated the 18.04 runners, which we need to support older versions of glibc.

My editor automatically ran prettier on the yaml file, I can revert that if reviewer has an issue.

[cretz]

LGTM. I don't mind the YAML cleanup. Let's wait for @mjameswh or @Quinn-With-Two-Ns to approve.

[cretz]

The proto submodule got inadvertently updated here, may want to put it back

[bergundy]

Looks like build is broken @mjameswh @Quinn-With-Two-Ns

> Task :temporal-serviceclient:compileJava
--
  | /temporal-java-client/temporal-serviceclient/src/main/java/io/temporal/serviceclient/LongPollUtil.java:33: error: cannot find symbol
  | \|\| method == WorkflowServiceGrpc.getUpdateWorkflowExecutionMethod()
  | ^
  | symbol:   method getUpdateWorkflowExecutionMethod()
  | location: class WorkflowServiceGrpc
  | /temporal-java-client/temporal-serviceclient/src/main/java/io/temporal/serviceclient/LongPollUtil.java:34: error: cannot find symbol
  | \|\| method == WorkflowServiceGrpc.getPollWorkflowExecutionUpdateMethod()) {
  | ^
  | symbol:   method getPollWorkflowExecutionUpdateMethod()
  | location: class WorkflowServiceGrpc

[bergundy]

Looks like I accidentally updated the submodule, build should fix itself.

[cretz]

You have to also push tags to your fork/branch. It's a known Java contributor annoyance atm.

[Quinn-With-Two-Ns]

LGTM, yeah features requires your git branch to have tags for Java

[Quinn-With-Two-Ns]

LGTM