binderRpcTest: ThreadPoolGreaterThanEqualRequested

This test fails 0.01% of the time, likely due to
scheduler interactions. We can make the test more robust
by using a secondary connection to the service, but
limiting noise from this case for now.

Fixes: 263370125
Test: binderRpcTest
Change-Id: I73fdbc9e232fc39ce579957fef32e94af606e56d