Added System API client for BackgroundInstallControlService

and added permission restriction to service APIs.

Deferring push mechanism for SystemAPI until new permissions are added.

OWNERS file will be updated separately in AOSP.

Resubmit after reversion of b/313009440, added permission provisioning in
BinaryTransparencyHostTest

Bug: 296060433
Test: atest BackgroundInstallControlServiceHostTest
 BackgroundInstallControlServiceTest
 BackgroundInstallControlCallbackHelperTest
 BinaryTransparencyHostTest
 GtsBackgroundInstallControlManagerTestCases
Change-Id: Ie7ec065a606b892990bcb74ad21c6d8fed3b285d