Don't use transport binder with the lock held

There was a deadlock around the transport lock. We registered transports
with the transport lock held, this kicked-off transport onCreate()
synchronously, which called TransportManager
updateTransportAttributes(), which tried to acquire mentioned lock but
couldn't. This CL removes the lock for any call to the transport or
operation that triggers a call to the transport (it was
TransportClient.connect() or its variants).

Test: Load GMSCore before fix, boot, register transports, check no ANR
Test: m -j RunFrameworksServicesRoboTests
Test: adb shell bmgr transport -c <transport>, being registered & not
Bug: 72147303
Change-Id: I72ca145d7fb73c0ef29c4aa1b620fea4969481db