Determine restore operation type through RestoreSet

Determining the operation type (e.g. cloud backup or device transfer)
through transport flags doesn't work during restore. A cloud transport
can still be responsible for restore of D2D data. Instead, determine the
operation type for each restore set individually.

Bug: 182986784
Test: atest FullBackupRulesHostSideTest
Change-Id: I8109b99a712e6a60a15164416751d45e632264d6