Enforce multipackage installs have consistent rollback params

PackageInstallerSession:
* Add multipackage consistency check to sealAndValidateLocked. The check
asserts all child sessions match parent session in respect to:
	* Staged parameter
	* Rollback enabled parameter
* Remove the staged conistency check from addChildSessionId
* Remove sealAndValidateLocked from constructor because it was used only
when sessions where loaded (from XML file) and there's no guarantee that
child sessions will be loaded before parent. Instead, mark the session
as ShouldBeSealed.

PackageInstallerService:
* To make sure relevant sessions are sealed and validated after they are
loaded from an XML file, iterate through the loaded seasions and seal and
validate those marked as ShouldBeSealed. Sessions that do not pass the
validation are destroyed.

Test: atest StagedRollbackTest
Test: atest CtsAtomicInstallTestCases
Test: atest PackageInstallerSessionTest
Fixes: 127765168
Fixes: 124215984
Change-Id: I8f152332cadb0f6c9063264f27668821fad1cec7