Add "exec" service: shell commands with no pty.
To facilitate device scripts that want to read/write binary data from
the host side, this change introduces a new "exec" service that
behaves like "shell" but without creating a pty, which would otherwise
mangle binary data.
After forking, it hooks up stdin/stdout of the child process to
the socket connected through to the host. The adb transport doesn't
support shutdown(), so the host can't half-close the socket and wait
for device termination. Instead, the host side now has two explicit
commands "exec-in" and "exec-out" for either sending or receiving
data.
Teach host side copy_to_file() to deal with stdin/stdout special
cases. Switch device side backup/restore services to use the new
create_subproc_raw under the hood.
Change-Id: I5993049803519d3959761f2363037b02c50920ee
5 files changed
