Use ThreadLeakMonitor for CSL2capProviderTest

This CL introduces ThreadLeakMonitor for CSL2capProviderTest.
ThreadLeakMonitor ignores threads with unique names, so all
L2capNetworkProvider related threads must specify a name.

Test: TH
Change-Id: I7cfcc93ab562a1ada2058d8c73e968a8d0005b1d
3 files changed