Fix oatdump for boot image extensions.

Fix the ParseCheckBootImage() to check the first component
of a multi-component boot image parameter.

Fix oatdump to fail nicely instead of aborting when it
fails to load any image.

Fix error message for boot image component count mismatch.

Test: m dump-oat (fails; check error message and exit)
Test: Manually run one of the `m dump-oat` commands with
      fixed --image argument (adding the primary image).
Change-Id: I4e143e3415b1239f6afee5fa18899a1724519155
3 files changed