C2SoftAacDec: Compute output port delay from stream info

Instead of hard-coding output port delay to 2, compute it
from stream info

Bug: 180567076
Test: poc in bug
Test: atest VtsHalMediaC2V1_0TargetAudioDecTest
Test: atest CtsMediaV2TestCases:CodecDecoderTest
Test: atest CtsMediaTestCases:DecoderTest
Test: atest CtsMediaTestCases:DecoderTestAacDrc
Test: atest CtsMediaTestCases:DecoderTestXheAac
Test: atest CtsMediaTestCases:DecoderTestAacFormat

Change-Id: I37d1a1f2ce0221f8b82ce4d61f8c8a09c4c55954