[audiopolicy] fix -Wreorder-init-list

C++20 will require members in a designated initializer to be in order
unlike C99.

Bug: 139945549
Test: mm
Change-Id: Ie129344a36893adc82e67181012e3af817bda9f4
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>