Make DNS cache lifecycle management explicit

1. ConnectivityService calls netd binder to create/destroy network directly.
2. Call dnsresolver binder to create/destroy cache after create/destroy network.
3. Remove unused network create/destroy methods in NetworkManagementService.

Bug: 129453995
Test: atest FrameworksNetTests
Change-Id: I15660d27f735e33d621d4af8972cdf115bf76dfa
5 files changed