g711 channel count limits

correct 'default to 6 channels' to 'default 1; max 6 channels'

Bug: 143163373
Test: vts-tradefed run vts --module VtsHalMediaC2V1_0Host
(cherry picked from commit 7a34a8bd9e15ea2b19b08087600bedf6806b8300)

Change-Id: Ifb6aa33f9f277883325f0b233d32aae53a429c5f
1 file changed