Add additional information to `argv[0]` when exec'ing.

Since all elements in `argv` show up tomestone, this allows us to show
additional information in tombstone.

It is particularly useful for Pre-reboot Dexopt, where we need a
noticable indication in tombstone to indicate that a process is run in
chroot.

Bug: 311377497
Test: m test-art-host-gtest-art_libarttools_tests
Change-Id: I3e5ebfa6927f712a04c0975d60bb154cca4355ae