Added support for 'bugreport -z'.

Dumpstate now supports zipped bugreport, whose output is more complete
than the flat-file bugreports provided prior to N.

The whole workflow is split in different components:

- adb supports a 'bugreport -z <ZIP_FILE>' option, which calls a
  bugreportz binary.
- bugreportz starts the dumpstatez service.
- dumpstatez starts dumpstate with some flags that opens a socket for
  control (not output).
- Once dumpstate is finished, it prints the bugreport location to
  stdout.
- adb pulls the zip file and renames according to the command-line
  argument.
- bugreport prints a deprecation message.

The reason for a new binary (bugreportz) instead of passing arguments to
bugreport (like -z) is backward compatibility: pre-N versions of
bugreport would ignore such argument and generate a text bugreport,
which is not what adb would be expecting.

BUG: 27653204

Change-Id: I47f6f677eba11d5fb54818ae5a0b3cab069776ee