SystemUI: always use transparent notification shade

Devices with less than 512MB of memory have a solid
black notification shade. Remove the isHighEndGfx()
check to force a transparent notification shade on
all devices.

Change-Id: I9a68a2a8b0d36685f8899f3bbed43bb6bccb47b1
"[+>" more icon was never shown in PhoneStatusBar

"[+>" more icon was never show in status bar because
the member variable for this icon was not initialized
from resources. This fix enables "[+>" icon to appear
in status bar when the number of indications in status
bar becomes large.

Bug: 8368569
Change-Id: Ieb3412eed831052d69c0cf63c9b4230c38171e4a
AudioService: Restore volumes after boot and when a headset is plugged

The correct volume levels for <device>_speaker and <device>_headset are not
restored after booting and when a headset device is plugged in or out.

This fixes a glitch where the first volume change event causes the volume to
be reset to the last stored value instead of increasing/decreasting it by
one step.

Change-Id: I6a483af34fd6d9dd706c6979202bf0cf26d80854