audio/hal: Set playback buffer size to integral multiple of msec

- Set the deep-buffer and low-latency output buffer sizes to
  integral multiple of msec. This reduces the variations in
  the writes.
- Compute the input buffer size based on sample rate. Use 20msec
  buffers in capture path.

Bug: 9283911, 9106434
Change-Id: Icbcb653f7f0fd3293dd4b514a54ac91d8311b308