Convert AudioAttribute to Stream correctly

When converting an AudioAttribute with FLAG_SCO set, it should
be converted to STREAM_BLUETOOTH_SCO. However, since getFlags()
returns only public flags, and FLAG_SCO isn't public,
the conversion will fail. Change to getAllFlags() to get right
flags.

Bug: 113314374
Test: Use AudioAttributes.toLegacyStreamType

Change-Id: Ic283f055d746d5c3df645dc310c92dac3c80827f