audio hal: fix assertion failed if mono input usb inserted

some usb input support only one channel, start the input channel
count from 1 to usb maximum channel to prevent assertion failed.
clean up extra loop on getting usb channel mask

Bug: 132040577
Test: build pass, mono input usb
Change-Id: Idcccc54c2e07b74c0580c8a8c0bf677c83aea715
Signed-off-by: vincenttew <vincenttew@google.com>
(cherry picked from commit e5de3abcdc0bf765957f929615b2008cd2b9a60c)
(cherry picked from commit 3e44f9f0a0ae9f309e05de57360ad58d053d2e29)