Make the runtime option -Ximage a ParseStringList

Previously, the string spliting is done in multiple code locations,
including ImageSpace::BootImageLayout::LoadOrValidate and
GetPrimaryImageLocation (which may be called multiple times).

This change converts the -Ximage option from a string into a
ParseStringList<':'>.

It may be worth pointing out that this doesn't change the current code
expectation that each image can have a profile (e.g.
"/path/to/foo.art!/some/profile.prof").

There is a later plan to introduce new options of boot image fds with
ParseIntList<':'>. This change would make them more consistent.

Bug: 187327262
Test: boot looks normal
Test: dexopt looks normal
Test: TH

Change-Id: I82657cb725cda2d3b782cbe7a6e6d9a871e80ee7
14 files changed