[pm] small refactor for InstallLocationUtils

+ Renaming to reflect the actual functionality of the class.

+ Move freeStorage related code to PackageManagerService, we will want
to clean that up later.

BUG: 198177734
Test: atest InstallLocationUtilsTest
Change-Id: I951129ffb5e53df548ef78fcd9de79c0ef994914
17 files changed