java_deobfuscate.py: Update regexp to match thread dump stacks

And simplify by having it use os.execv().

The lines in question look like:
06-22 13:58:02.895  4674  4674 E THREAD_STATE:     bLA.a(PG:173)

BUG=713710

Review-Url: https://codereview.chromium.org/2952283002
Cr-Original-Commit-Position: refs/heads/master@{#481801}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 3a2065e70c18fc516374f011048cca308cf8ffa9
1 file changed