Add method to remove test from tracked loopers

Add method to remove a test from the sLoopers map, since keeping them
around forever results in a memory leak for large test suites.

Bug: 156287358
Test: atest FrameworksTelephonyTests
Change-Id: I553ea3a1dac3ff4107e0c7caabee26d21f4c52f8
1 file changed