Update to sendAllRequestsToProvider for Multilayer

Updates to ConnectivityService.sendAllRequestsToProvider to support
Multilayer requests.

Bug: 175051182
Bug: 171991028
Test: atest FrameworksNetTests
atest FrameworksNetIntegrationTests
atest CtsNetTestCasesLatestSdk

Change-Id: Id7a6175cee28d2de1f6194cd0fc8c739d667427d