Revert^2: dexopt: Fix target-sdk-version argument creation

Refactor CL I8fdf96cfe0343042d1a868ca09e6c6b9a629b967 has a typo
which leaves the target-sdk-version argument of dex2oat always empty.
Fix the issue.

This reverts commit 14283651.

Test: manual inspection of command line arguments
Test: adb shell pm compile -m speed <package>
Change-Id: I6b92e8c595e3c00d71ab13d976ee43f58d1a0013