Cache network capabilities to reduce the number of calls
ConnectivityController makes to ConnectivityManager.

Bug: 164460449
Bug: 166702583
Test: atest com.android.server.job.controllers.ConnectivityControllerTest
Test: atest CtsJobSchedulerTestCases
Change-Id: I501e5153d7bffd2494aec484c74b9e1b6252aeeb
(cherry picked from commit 6f9ab029)