Use the Telecom lock in Telecom.Runnable

To prevent deadlocks in Telecom when using Session Runnables, we will
now lock on the main Telecom Lock instead of an independent lock inside
of Telecom.

Bug: 31076766
Change-Id: I993d7f2e8b077f89daef72ce1ca7b7fad2ad8823
(cherry picked from commit f5e06660)