Fixed stylus eraser being rejected by palm rejection

The stylus eraser appeared not to work, i.e. Android did not respond to
input from the eraser. It turned out that all input except stylus input
is rejected when palm rejection is activated. The problem was that the
eraser itself activates palm rejection when it hovers. The solution is
to allow the eraser during palm rejection. This solution makes sense
because the eraser input works in the exact same way as normal stylus
input.

Change-Id: I90824500be7613af4f00427c59ce828528b632f7
Base: Disable proximity sensor when screen goes on in ActiveDisplay/PocketMode.

Active Display (in Pocket Mode) currently only switches off the proximity sensor in some cases.
If the user switches on the screen itself, the sensor is left running. This change
stops the sensor as soon as the screen goes on. Active Display already started the sensor each
time the screen goes off.

PS2: In the mode that turns the screen off again when the device is pocketed,
the sensor stays on until you leave ActiveDisplay.

Change-Id: Id7afcd858f341ad929606d302c5741efa99a7c6f
MediaFocusControl: Deny audio focus if notification stream is 0

Previously audio focus would be granted regardless of notification
volume, meaning that if notifications are muted the media stream would
still be dimished for focus. By checking if STREAM_NOTIFICATION is 0 and
if a notification stream is requesting focus, this is no longer an issue.

Change-Id: Ie10a64e58ce77174a3bbdeaa936646d40c24404f
Signed-off-by: Evan Anderson <evan1124@gmail.com>
Set Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE default value

To be able to customize the "WiFi scan always available"
setting we need to set a default value.

Change-Id: I3673f2613ab9b6a947aed7e29d4cc876140c2180