Add a new aaudio callback function.

The new callback function will allow apps to partially process the
provided data.

Bug: 406332239
Test: atest AAudioTests
Test: OboeTester data path test
Flag: com.android.media.aaudio.new_data_callback
Change-Id: I5f64eef8f229d3e0b7a8bc999127114fe0422b98