aaudio: add callback size options to examples

This can be used to reproduce the wrap around bug
in the MMAP FIFO in OC_MR1.

Bug: 78139448
Test: aaudio_loopback -tm -pl -Pl -z120
Change-Id: I923e60432f1c9777355d12d76609f2d70393f61b
Merged-In: I923e60432f1c9777355d12d76609f2d70393f61b