Refactor argument creation to be before the fork

Since it's not safe to do allocations between the fork and the exec,
refactor all of the argument creation to be done before the fork.

Test: adb shell data/nativetest/installd_dexopt_test/installd_dexopt_test

Change-Id: I97016affb32b7ad908861976a1c46d3c4bd816d7