Add a test to identify memory leak in ConnectivityManager

The sInstance static instance which self reference to
ConnectivityManager which holds a reference to a ConnectivityManager
instance causes the Context referenced by that instance to never be
GCed.

Bug: 202978965
Test: atest ConnectivityManagerTest
Change-Id: I0227f63dbc27688ea5f4ef9275fd0f9c247ad14c
1 file changed