[pm/incremental] start monitoring progress on storage creation

For Incremental installs, the installation progress will be equal to the
loading progress, which is the percentage of filled blocks divided by
the total number of blocks. The installation progress reported from the
client will be ignored. This is for a smoother visual transition between
installed state and loading state, as reflected in the launcher UI.

See timestamp 00:26 in video:
https://drive.google.com/file/d/11Z4IwUvaoMx0QZVboq7idxu4PUZZcGw-/view?usp=sharing&resourcekey=0-EQDzWobRTJxTQCCGUfbXQA

It reflects the <25% of loading progress instead of the 100% installation
progress, though not very visible.

BUG: 172082017
Test: manual
Change-Id: I30bac011fc4fe431960570640e6ced55b01c0234