system: Support for offloading Java audio tracks

Offload Java audio tracks if the property is set.
This is used to avoid mixing in audioflinger and
to apply effects in DSP. Also update function to
calculate bytes per sample for offload format.

Change-Id: I0705e70a806a335e372e844de8a1210fbfe58cd7
logd: throttle SELinux denials to 20/sec

Impose a limit of 20 selinux denials per second. Denials beyond
that point don't add any value, and have the potential to cause
crashes or denial of service attacks.

Do some other misc cleanup while I'm here.

Bug: 18341932
Change-Id: I6125d629ae4d6ae131d2e53bfa41e1f50277d402
healthd: Reinitialize mChargerNames for every battery update

Booting up the device without the usb sets the usb power supply
type as UNKNOWN. Due to this mChargerNames gets incorrectly
initialized at bootup. The value of usb power supply type changes
at run-time. So it makes sense to update mChargerNames everytime
we have a battery related update.

Change-Id: I2ec9f9a420ca61814d43c316b418ce94de3691bc
audio: Add 24-bit offload format to audio_bytes_per_sample

Change-Id: I238f302beadf8ba7705ffcb70639fb32be4ff2c4