record-finalized-flags: add actual implementation

From the command's --help text:

---- 8< ----
The prebuilts/sdk/<version>/finalized-flags.txt files list all aconfig flags that have been used
with @FlaggedApi annotations on APIs that have been finalized. These files are used to prevent
flags from being re-used for new, unfinalized, APIs, and by the aconfig code generation.

This tool works as follows:

  - Read API signature files from source tree (*current.txt files) [--api-signature-file]
  - Read the current aconfig flag values from source tree [--flag-file]
  - Read the previous finalized-flags.txt files from prebuilts/sdk [--finalized-flag-file]
  - Extract the flags slated for API finalization by scanning through the API signature files for
    flags that are ENABLED and READ_ONLY
  - Merge the found flags with the recorded flags from previos API finalizations
  - Print the set of flags to stdout
---- >8 ----

Bug: 377676163
Test: atest record-finalized-flags-test
Merged-In: Icde8c63fc54791429865168989bfb6af01845d15
Change-Id: Icde8c63fc54791429865168989bfb6af01845d15
12 files changed
tree: b27fbf3f038c9d210f8b48032c1680557c7ec14b
  1. backported_fixes/
  2. ci/
  3. common/
  4. core/
  5. packaging/
  6. target/
  7. teams/
  8. tests/
  9. tools/
  10. .gitignore
  11. Android.bp
  12. banchanHelp.sh
  13. buildspec.mk.default
  14. Changes.md
  15. CleanSpec.mk
  16. Deprecation.md
  17. envsetup.sh
  18. help.sh
  19. navbar.md
  20. OWNERS
  21. PREUPLOAD.cfg
  22. rbesetup.sh
  23. README.md
  24. shell_utils.sh
  25. tapasHelp.sh
  26. Usage.txt
README.md

Android Make Build System

This is the Makefile-based portion of the Android Build System.

For documentation on how to run a build, see Usage.txt

For a list of behavioral changes useful for Android.mk writers see Changes.md

For an outdated reference on Android.mk files, see build-system.html. Our Android.mk files look similar, but are entirely different from the Android.mk files used by the NDK build system. When searching for documentation elsewhere, ensure that it is for the platform build system -- most are not.

This Makefile-based system is in the process of being replaced with Soong, a new build system written in Go. During the transition, all of these makefiles are read by Kati, and generate a ninja file instead of being executed directly. That's combined with a ninja file read by Soong so that the build graph of the two systems can be combined and run as one.