Fix one child MultiPackage session user action fails

* validateApkInstallLocked stores the target SDK version of the base
  apk in mValidatedTargetSdk used in IsSolvedUserAction.
* Moves checking UserAction stuff from prepareForVerification to
  IsSolvedUserAction.
* setPermissionsResult triggers either itself or its parent session
  to be installed.
* Package Verification gets rid of UserAction

Fixes: 183919452
Test: atest CtsSilentUpdateHostTestCases CtsPackageInstallTestCases

Change-Id: I2be662c91f46299da2e47aa8531df33ba2f8e8c3