Capture all exceptions rather than just IO ones.

If an exception which isn't in the IOException hierarchy gets
thrown within this code it can bring down the system_server, so
we should capture and log any exception rather than letting it
propagate out and bring down system_server.

I decided not to capture all Throwables because they represent
more serious runtime errors that probably should bring down
system_server.

Fixes: 140472631
Test: m -j (compilation means we're OK).
Change-Id: Ibbd9612d1e9b42c100ce7fda0b7463ac3f10704e