Fix ConnectionPoolTest bug

[ean5533]

1. Advance taskFaker time forward to the present when the test starts.
   • Fixes a problem introduced in Fake time in ConnectionPoolTest #8360
2. Stop having multiple factories and taskfakers floating around.

[yschimke]

I merged because it looked to be passing

But still seeing failures.

ConnectionPoolTest > connectionPreWarmingHttp2() FAILED
    org.opentest4j.AssertionFailedError: expected:<[2]> but was:<[1]>
        at app//okhttp3.internal.connection.ConnectionPoolTest.connectionPreWarmingHttp2(ConnectionPoolTest.kt:258)

[ean5533]

Yup, I'm working on that now, just wanted to get these easy wins merged in first. I've found the root cause of the flakiness in that test (the use of TaskRunner.INSTANCE in Http2Connection.Builder) but I'm not yet sure how to fix it.