Remove PMS snapshot lambdas

Lambdas were used to ensure consistent locking around the snapshot,
but since it's impossible to lock the snapshot now, this is no longer
necessary, and all methods should just store a reference.

Also migrates DomainVerificationService off PackageSetting lambdas,
which cleans up a lot of extra emthods.

Bug: 215403184

Test: atest com.android.server.pm.verify.domain
Test: atest SuspendPackageHelperTest

Change-Id: Ib4e3442e5c16e935b14b8421fbc33adff65dcf68