[flutter_tools] Apply --no-causal-async-stacks and --lazy-async-stacks to profile/release builds (#49377)

[flutter_tool] Refactor Logger and Terminal to (mostly) no longer depend directly on context (#47269)

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

Analyzer warning.

This reverts commit 3597bae6.

...because otherwise, processes that think they're manipulating your
filesystem will be doing crazy things the test is ignoring, leading to
(at best) failures and (at worst) flakes or disk corruption.

* Unit test for build.dart::GenSnapshot

* Fix analysis errors

* Switch to testLogger

This reverts commit 202c1b42.

Move tools tests into a general.shard directory in preparation to changing how we shard tools tests (#36108)

Android now exclusively uses ELF shared libraries, and
iOS uses assembly.

AOT compiled code is now packaged as an ELF library for Android targets.
By default gen_snapshot's output contains debug symbols.  The symbols could
be stripped as a separate step, but that requires NDK tools that the user
may not have available.

This change passes a gen_snapshot flag that omits the symbols, and it filters
out a warning printed when that flag is used.

* Gradle generates ELF shared libraries instead of AOT snapshots.
* `flutter build apk/appbundle` supports multiple `--target-platform` and defaults to `android-arm` and `android-arm64`.
* `flutter build apk` now has a flag called `--split-per-abi`.

Revert "Generate ELF shared libraries and allow multi-abi libs in APKs and App bundles (#33696)" (#34121)

* Gradle generates ELF shared libraries instead of AOT snapshots.
* `flutter build apk/appbundle` supports multiple `--target-platform` and defaults to `android-arm` and `android-arm64`.
*  `flutter build apk` now has a flag called `--split-per-abi`.

Splits Xcode validation out of the iOS validator and into a stand-alone
validator, and groups the CocoaPods validator with that top-level
validator instead of the iOS validator. iOS now validates only the
iOS-specific tools (e.g., ideviceinstaller).

Reorganizes many of the associated clases so that those that are used by
both macOS and iOS live in macos/ rather than ios/. Moves some
validators to their own files as part of the restructuring.

This is the macOS portion of #31368

This is the correct metric to report for compilation time benchmarks rather
than RunTime. Rename the 'gen_snapshot' value to merely 'snapshot' for
backwards compatibility and overall simplicity.

This change simplifies Dart's benchmarking of Flutter by making it easier to
adopt --report-timings (made for Dart to use), which makes the benchmarks
much more robust.