AAudio: Handle weird callback sizes better

For a callback size of 7, AAudio output streams often glitch.

This happens when the wrapping buffer is almost empty. In these cases,
AAudio should be careful and put only one frame at a time.

This CL also adds some breaks to mimic the code before a SRC was added
to AAudio.

Bug: 310282314
Test: OboeTester Test Output
Change-Id: I2c2106a4727bcb3d880883b7ac494fea26fe7d96