commit 01ea57c593405963274c757bf24b1e95a8b4b6e7
author Paul Duffin <paulduffin@google.com> Mon Jan 17 16:39:00 2022 +0000
committer Paul Duffin <paulduffin@google.com> Mon Feb 07 14:12:17 2022 +0000
tree 3f9f36001334c9ebd18facb33e8adf9fa6bc5546
parent 6ea0eb45c5d67806d70bb9d70a33d2cddbc4eea1

Support building build target specific snapshots

This changes adds support for building target build release specific
snapshots.

It adds a BuildRelease class that defines the characteristics of the
build release, e.g. name, how to create it, etc. It also adds a
first_release field to MainlineModule which specifies the first
BuildRelease for which a snapshot of the module is required and
initializes that field for each module.

After these changes this script will generate:
1. A legacy set of snapshots that match the file structure that was
   generated without this change. This is intended to allow existing
   consumers of the generated artifacts to continue to work while they
   are modified to make use of target build release specific snapshots.

2. The set of snapshots for the latest build release, i.e. the build
   release containing the source from which the snapshots are produced.
   This includes snapshots for all the modules.

3. For each build release from S onwards a set of snapshots for the
   modules it supports.

It does not currently generate snapshots for Q and R releases as Soong
cannot generate a compatible snapshot for them. If it is necessary to
generate snapshots for those target build releases (similar to what the
packages/modules/common/generate_ml_bundle.sh would produce) then a
follow up change will add that capability to this script.

Bug: 204763318
Test: atest mainline_modules_sdks_test
      packages/modules/common/build/mainline_modules_sdks.sh
      tree out/dist/mainline-sdks out/dist/stubs
      - check that it adds the for-latest-build directory but is
        otherwise identical to what was produced before this change.
Change-Id: I48eb0b69cbe8664106b826ee0898557c98e039c2