Detect downgrade by checking build time for all partitions

Checking ro.build.date.utc to detect a downgrade is not enough in the
case where several target files are merged, as timestamps can differ
for each partition.

The solution is to check the build timestamp for each partition and
ro.build.date.utc.

With this change ota generation will be aborted during creation
instead of rejected when installing on device.

This also fixes the --override_timestamp so it is possible to generate
a package where timestamps are reversed, as was added in:
3e6161a3b33da5a46c80c79e2d815168923e83c3.

Issue: 315913966
Test: Manual, confirm that ota generation is aborted when timestamp
  on post vendor partitions is newer than on pre.
  Ota created successfully with --override_timestamp parameter and
  installation successful
Test: atest --host releasetools_test
Change-Id: I275e67a3840f4ef2263381c253231068e72f47d2
3 files changed
tree: 69fad20084e7707ae3bd0c00681c7c405c410ff7
  1. common/
  2. core/
  3. packaging/
  4. target/
  5. tests/
  6. tools/
  7. .gitignore
  8. banchanHelp.sh
  9. buildspec.mk.default
  10. Changes.md
  11. CleanSpec.mk
  12. cogsetup.sh
  13. Deprecation.md
  14. envsetup.sh
  15. help.sh
  16. METADATA
  17. navbar.md
  18. OWNERS
  19. PREUPLOAD.cfg
  20. rbesetup.sh
  21. README.md
  22. shell_utils.sh
  23. tapasHelp.sh
  24. 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For an outdated reference on Android.mk files, see build-system.html.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.