build: Add Lineage build support

Squashed also with the following changes:

  Author: Luca Stefani <luca020400@lineageos.org>
  Date:   Thu Aug 17 22:22:13 2017 +0200

    core: Include Lineage pathmap

  Change-Id: Ie25dee383cc5bc9bb6390cff2cb2460d526d80b6

  Author: Simon Shields <simon@lineageos.org>
  Date:   Fri Mar 2 12:55:47 2018 +1100

    build: unconditionally use lineage pathmap

    even if we're not building a lineage target, we need to
    use the lineage pathmap to make things like recovery and ril
    happy

  Change-Id: I974c30ad10d4ff5b7805c3df9c22010f1e002bf1

  Author: Luca Stefani <luca.stefani.ge1@gmail.com>
  Date:   Tue Jan 22 15:50:52 2019 +0100

    Don't export BUILD_NUMBER in envsetup

    * The value is meant to be set only before running an /official/ build
    * This allows us to execute consecutive make commands without
      running kati for every invocation

  Change-Id: Ifa94b839f30c7260009c8a3c91c202b50e28022e

  Author: Luca Stefani <luca020400@lineageos.org>
  Date:   Fri Aug 18 10:17:00 2017 +0200

    envsetup: Call fixup_common_out_dir

  Change-Id: I84e16b0df5822cfd8514c46d709109a13c20f86e

  Author: Adrian DC <radian.dc@gmail.com>
  Date:   Sat May 12 11:24:33 2018 +0200

    build: Include LineageOS specific properties in build.prop

     * Our properties were supposed to go to /system/etc/prop.default
        after the following commit:
        "lineage: Move to Google's method of defining system default props"
        Change-Id: I6cb0e28a7599b010b389cc541015a37010a00f4b

     * However if BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED is not true,
        only /default.prop will retain the properties contents of
        ADDITIONAL_DEFAULT_PROPERTIES and PRODUCT_SYSTEM_DEFAULT_PROPERTIES,
        and none of our versioning identification was held in the system

     * Enabling BOARD_PROPERTY_OVERRIDES_SPLIT_ENABLED globally would
        break all properties on devices that handle partitions usually
        at the device level rather than the kernel due to mounting races

     * Include the vendor/lineage/config/main.mk entrypoint to be allowed
        to extend ADDITION_BUILD_PROPERTIES as we need to define our releases

  Change-Id: I19918eece0f0dd3ee967db0339b4d09c9a6d540e
Signed-off-by: Adrian DC <radian.dc@gmail.com>

  Author: Simon Shields <simon@lineageos.org>
  Date:   Fri Aug 10 14:39:32 2018 +1000

    soong: include Lineage soong_config

    Change-Id: Ic7b8993f4a201f8a9d24c6ba32617fa34843afc2

  Author: Rashed Abdel-Tawab <rashed@linux.com>
  Date:   Thu Sep 5 21:35:38 2019 -0700

    core: Only include Lineage SE policy if repo exists

  Change-Id: If799106d2da6d8c303430e316edff365a22f7c99

  Author: dianlujitao <dianlujitao@lineageos.org>
  Date:   Thu Sep 5 21:56:36 2019 +0800

    product: Exclude AOSP apn list on Lineage build

    Change-Id: I1fd10089421a2e4b57ef565d87ad1f6036bd1898

  Author: Michael Bestas <mkbestas@lineageos.org>
  Date:   Fri Apr 12 02:10:12 2019 +0300

    build: Conditionally include AudioPackage14.mk instead of AllAudio.mk

    * AllAudio.mk doesn't contain latest material files and also
      contains multiple duplicate files. Just copy the latest
      material ones and we'll include the older files in vendor/lineage

    Change-Id: Ic7353216a3f3dc3c51006d951ac932cfd6e5f3b5

  Author: dhacker29 <dhackerdvm@gmail.com>
  Date:   Sat Jun 6 22:22:05 2015 -0400

    Remove LatinIME as it is included per target in vendor/lineage

    Change-Id: Ibce4a244ec0653a7c7798d864047ac667866a1dc

  Author: Arne Coucheron <arco68@gmail.com>
  Date:   Sat Mar 3 22:53:06 2012 +0100

    Fix inheritance of PRODUCT_PROPERTY_OVERRIDES for Lineage audio files

    Otherwise the ones set in Lineage vendor will be overridden by these.

    Change-Id: I3f87dfd009d8ddfd48972c15770599742b12c4af

    Author: Abhisek Devkota <ciwrl@cyanogenmod.com>
    Remove extra product property overrides

    This appears to clash with vendor/lineage/common mk's for overrides; causes
    a broken default alarm (and OnTheHunt is so bleh).

    Change-Id: I5ec990d3c5ad56b573c45f1a3b20169c989851a0

  Author: Pawit Pornkitprasan <p.pawit@gmail.com>
  Date:   Sat Jan 28 09:05:16 2012 +0700

    Disable dataroaming by default

    The property is removed so that the property in vendor/lineage
    can take effect.

    Change-Id: Iefadc1a6e71cbf92ecb7363c953f4b5a82064446

  Author: razorloves <razorloves@gmail.com>
  Date:   Mon Oct 7 05:10:56 2019 -0500

    build: Remove su inclusion

    This stops including su in all lineage userdebug/eng builds.
    Inclusion of su is conditionally handled in /vendor/lineage.

    Change-Id: Ia3ad978146f170a2b260d77afe9eb580d4b4f823

Change-Id: Iab8b2ef8b644a7bea10bfd28b99d9e69539b1357