Prepare installd to handle profiles per code path

Transform each profile operation to accept the pair
(package_name, profile_name). This will allow installd to get the profile
name from the PackageManager instead of assuming a predefined name. The
PackageManager will compute and assign unique profile names for each code
path.

The end goal is to support installation and extraction of profiles per
code path.

Also, add a few extra tests for merging the profiles.

Test: installd_dexopt_test, installd_utils_test
Bug: 30934496
Change-Id: I580f037d9d3e5537032e815dc803b9ddeff343cb