[Android] [supersize] Run objdump from an output directory during disassembly

objdump when run from within an output directory can pull lines from
source files and interleave within the disassembly.

Change-Id: I15b6c559b04b28c31adb5464f853b8df7336f5f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2923684


Commit-Queue: Mohamed Heikal <mheikal@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Auto-Submit: Mohamed Heikal <mheikal@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#887360}