Query installed storage for installed apps

Query installed storage for installed apps

Change in logic:
 - for installed apps query pkgmgr,
 - for new apps set internal storage by default;
   installed_storage value is overwriten in StepAcquireExternalStorage
   if initialization of sd card works well.

This is just some factoring. To verify:
 - run smoke tests for tpk,
 - check that move request is still working:
     tpk-backend -i ${package}
     tpk-backend -m ${pkgid} -t 1
     tpk-backend -m ${pkgid} -t 2

Change-Id: Id24ab0667e356917f2ed10dd36a6cef1e58edf95