debuggerd: fix passing of fdsan_table to crash_dump

Commit aosp/1259140 moved fdsan_table into debugger_process_info, which
is populated conditionally. This introduced a bug where the process that
receives BIONIC_SIGNAL_DEBUGGER (35) does not propagate the fdsan_table
pointer to crash_dump:

  $ adb shell kill -SIG35 <pid>
  $ adb logcat -s DEBUG
  E DEBUG   : failed to read fdsan table entry 0: I/O error

Fdsan in warn-only mode uses BIONIC_SIGNAL_DEBUGGER[1], so the generated
tombstones don't have any fd ownership info.

Fix it by calling get_process_info() irrespective of the signal being
handled, taking care to preserve the previous behavior of not showing
abort messages set by applications in non-fatal dumps.

Test: debuggerd_test
Test: send SIG35 to arbitrary process and inspect the log and tombstone
Test: crasher fdsan_file

[1] https://android.googlesource.com/platform/bionic/+/20ad9129e7115417fcd1da922693947580b7f0a6/libc/bionic/fdsan.cpp#166

Change-Id: I76931ca4825e846fc99f26fa590c045130abb850