Skip DumpForSigQuit if debugger is active

Otherwise, the SIGQUIT dumping may get blocked on the mutator lock
and freeze the debugger.

Future work: Ideally we want to dump what we can instead of nothing.

Bug: 26118154

(cherry picked from commit 0b8f1bfdfc721a41d98d13e12c4c67f62f698dfc)

Change-Id: I28e5352dab3b8abce0b39850e3e58282ae454b51
1 file changed