Use audio_has_proportional_frames when setting up AudioTrack.

When setting up AudioTrack in JNI, using audio_is_linear_pcm to compute
frame count will make IEC61937 track using a bigger buffer. We should use
audio_has_proportional_frames instead.

Bug: 31914407
Test: Play IEC61937 track and check memory size
Change-Id: I2a907db1d8b256076e1c83b47b67684a539deaaa