[HWASan] Improve symbol indexing (#135967)
Previously we would add any ELF that contained a build id regardless
whether the ELF contained symbols or not. This works for Android since
soong will strip the symbols into a new directory. However other
build systems, like BUCK, will write the stripped file in the same
directory as the unstripped file. This would cause the hwasan_symbolize
script sometimes add then stripped ELF to its index and ignore the
symbolized ELF. The logic has now been changed to only add ELFs that
contain symbols to the index. If two symbolized ELFs are encountered
with the same build id, we now exit out with an error.
Fixes #135966
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Co-authored-by: Stefan Bossbaly <sboss@meta.com>
