SystemUI: runtime configurable audio panel location

* Placement is now determined at runtime by a lineage setting.
  Use TunerService to track settings change.
  Various cleanup and fix formatting.
  Fixed left/right gravity on expand arrow and ringer.
  Fix commit author.
  (sam3000)

This is a squashed and adapted commit of the following patches:

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  From cf187bd54fbd807e16b0ac3593e839008efd302e Mon Sep 17 00:00:00 2001
  From: "a.derendyaev" <a.derendyaev@magdv.com>
  Date: Wed, 19 Dec 2018 21:57:45 +0800
  Subject: [PATCH] SystemUI: allow devices override audio panel location

  Some devices have volume buttons on left side and it not fancy if volume panel will be at right side.
  You can override panel location using overlay for SystemUI:

  <!-- Allow devices override audio panel location to the left side -->
  <bool name="config_audioPanelOnLeftSide">true</bool>

  Change-Id: I8a2302867010b0e6a02efa68df57e534ce7bbf46
  Signed-off-by: Jagrav Naik <jagravnaik0@gmail.com>
  Signed-off-by: Anirudh Gupta <anirudhgupta109@gmail.com>

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  From 9d0ff1efd26961a4f14d0821f50ebe80c2a65ff9 Mon Sep 17 00:00:00 2001
  From: Alex Cruz <alex@dirtyunicorns.com>
  Date: Fri, 21 Dec 2018 22:08:52 -0600
  Subject: [PATCH] Volume panel: Do the same with less

  Use common volume_dialog layout for both left- and right-aligned panel

  [@TheDorkKnightRises - POSP]
  - Tweak padding values to make them uniform across both alignments
  - Remove redundant comment

  Change-Id: If41456f71ffd18466166e7b4120ff34d9e6f5a46
  Signed-off-by: Josh Fox (XlxFoXxlX) <joshfox87@gmail.com>

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Change-Id: I9345d83af52cadf9f196fb341e27265af09d5aec