audio policy: fix gapless playback when effects enabled

Do not allow offloading if one non offloadable effect is enabled. This prevents from
creating an offloaded track and tearing it down immediately after start when audioflinger
detects there is an active non offloadable effect.
Not doing so breaks gapless playback because AwesomePlayer will always be able to open
an offloaded track which will not be compatible with the previous PCM track and
Audiosink::open() will not recycle it.

Bug: 11181933.
Change-Id: I6d163806849d9093b9ec701ba8e8c1ccb658e3c8
2 files changed