aaudio example: add dynamic workload test

Add options to write_sine_callback example.
-w  set base workload
-W  alternate between base and this workload
-Z  set period in seconds for alternating workloads
-a  set CPU affinity

Bug: 202441352
Bug: 202345376
Test: adb shell write_sine_callback -pl -n4 -w1.0 -W14.0 -a2 -Z3
Change-Id: Id25d651dc0ac9befff1fc1af1132753dd7482c7c